Home
Search results “Primary structure amino acid bonds”
Four levels of protein structure | Chemical processes | MCAT | Khan Academy
 
08:49
The four levels of protein structure are primary, secondary, tertiary, and quaternary. It is helpful to understand the nature and function of each level of protein structure in order to fully understand how a protein works. By Tracy Kovach. Created by Tracy Kim Kovach. Watch the next lesson: https://www.khanacademy.org/test-prep/mcat/chemical-processes/amino-acids-peptides-proteins-5d/v/conformational-stability-protein-folding-and-denaturation?utm_source=YT&utm_medium=Desc&utm_campaign=mcat Missed the previous lesson? https://www.khanacademy.org/test-prep/mcat/chemical-processes/amino-acids-peptides-proteins-5d/v/classification-amino-acids?utm_source=YT&utm_medium=Desc&utm_campaign=mcat MCAT on Khan Academy: Go ahead and practice some passage-based questions! About Khan Academy: Khan Academy offers practice exercises, instructional videos, and a personalized learning dashboard that empower learners to study at their own pace in and outside of the classroom. We tackle math, science, computer programming, history, art history, economics, and more. Our math missions guide learners from kindergarten to calculus using state-of-the-art, adaptive technology that identifies strengths and learning gaps. We've also partnered with institutions like NASA, The Museum of Modern Art, The California Academy of Sciences, and MIT to offer specialized content. For free. For everyone. Forever. #YouCanLearnAnything Subscribe to Khan Academy’s MCAT channel: https://www.youtube.com/channel/UCDkK5wqSuwDlJ3_nl3rgdiQ?sub_confirmation=1 Subscribe to Khan Academy: https://www.youtube.com/subscription_center?add_user=khanacademy
Views: 549690 khanacademymedicine
Amino Acids and Levels of Protein Structure
 
10:37
Amino Acids and Levels of Protein Structure 1. Introduction 2. Monomers and polymers (dehydration synthesis and hydrolysis reactions) 3. Parts of an amino acid 4. Peptide bonds 5. The way to study amino acids: groups based on shared chemical characteristics 6. Levels of protein structure: Primary: sequence of amino acids Secondary: regions of regular folding due to H-bonds between amino and carboxyl groups that are close together in the polypeptide chain. Alpha helices and beta sheets. And penguins in my kitchen. Tertiary: chemical interactions between R groups Quaternary: interactions between 2 or more polypeptide chains Videos Mentioned: Chemistry Basics I: http://youtu.be/MYuh5yErdfA Chemistry Basics II: http://youtu.be/Juw7HBg0zZs Signal Transduction: http://youtu.be/pH_ibPHK0y0 How Hormones Work: http://youtu.be/KnIu7DDflw8 Just want more Penguin Prof? Subscribe: http://www.youtube.com/user/ThePengui... FB Page: https://www.facebook.com/ThePenguinProf Twitter: https://twitter.com/penguinprof Web: http://www.penguinprof.com/ Penguin Prof is Supported BY AUDIBLE.COM PenguinProf LOVES Audible and now the feeling is mutual! Audible.com is the premier provider of digital audiobooks. Audible has over 150,000 titles to choose from in every genre. Audible titles play on iPhone, Kindle, Android and more than 500 devices for listening anytime, anywhere. Click to learn more and download a FREE audiobook of your choice! http://www.audibletrial.com/PenguinProf
Views: 1158 ThePenguinProf
Primary Structure of Proteins
 
16:07
Donate here: http://www.aklectures.com/donate.php Website video link: http://www.aklectures.com/lecture/primary-structure-of-proteins Facebook link: https://www.facebook.com/aklectures Website link: http://www.aklectures.com
Views: 96919 AK LECTURES
Protein Structure
 
10:50
Everyone has heard of proteins. What are they on the molecular level? They're polymers of amino acids, of course. They make up most of your body, so we have to understand their structure very well! Check this out to learn the hierarchy of protein structure so that we can later learn all about what different types of proteins can do. Subscribe: http://bit.ly/ProfDaveSubscribe [email protected] http://patreon.com/ProfessorDaveExplains http://professordaveexplains.com http://facebook.com/ProfessorDaveExpl... http://twitter.com/DaveExplains General Chemistry Tutorials: http://bit.ly/ProfDaveGenChem Organic Chemistry Tutorials: http://bit.ly/ProfDaveOrgChem Biochemistry Tutorials: http://bit.ly/ProfDaveBiochem Classical Physics Tutorials: http://bit.ly/ProfDavePhysics1 Modern Physics Tutorials: http://bit.ly/ProfDavePhysics2 Mathematics Tutorials: http://bit.ly/ProfDaveMaths Biology Tutorials: http://bit.ly/ProfDaveBio American History Tutorials: http://bit.ly/ProfDaveAmericanHistory
Views: 222883 Professor Dave Explains
Amino acid structure | Chemical processes | MCAT | Khan Academy
 
10:55
In this video, you'll learn about the general structure of amino acids, which include an amine group, a carboxylic acid group, and a unique side chain (R-group) attached to the alpha carbon. In addition, we'll explore where amino acids fit in terms of biological metabolism. By Tracy Kovach. . Created by Tracy Kim Kovach. Watch the next lesson: https://www.khanacademy.org/test-prep/mcat/chemical-processes/amino-acids-peptides-proteins-5d/v/isoelectric-point-and-zwitterions?utm_source=YT&utm_medium=Desc&utm_campaign=mcat Missed the previous lesson? https://www.khanacademy.org/test-prep/mcat/chemical-processes/amino-acids-peptides-proteins-5d/v/special-cases-histidine-proline-glycine-cysteine?utm_source=YT&utm_medium=Desc&utm_campaign=mcat MCAT on Khan Academy: Go ahead and practice some passage-based questions! About Khan Academy: Khan Academy offers practice exercises, instructional videos, and a personalized learning dashboard that empower learners to study at their own pace in and outside of the classroom. We tackle math, science, computer programming, history, art history, economics, and more. Our math missions guide learners from kindergarten to calculus using state-of-the-art, adaptive technology that identifies strengths and learning gaps. We've also partnered with institutions like NASA, The Museum of Modern Art, The California Academy of Sciences, and MIT to offer specialized content. For free. For everyone. Forever. #YouCanLearnAnything Subscribe to Khan Academy’s MCAT channel: https://www.youtube.com/channel/UCDkK5wqSuwDlJ3_nl3rgdiQ?sub_confirmation=1 Subscribe to Khan Academy: https://www.youtube.com/subscription_center?add_user=khanacademy
Views: 352030 khanacademymedicine
Protein - Structure Of Protein - What Is Protein Made Of - Structure Of Amino Acids Building Blocks
 
04:23
In this video we discuss the structure of protein and the structure of amino acids. We cover how amino acids link together to form proteins. Transcript/notes Protein structure All Proteins contain 4 elements, carbon, hydrogen, oxygen and nitrogen, however, some proteins contain phosphorus, sulfur, iron, zinc, magnesium and other trace metals. Proteins are giant macro molecules that are made up of amino acid building blocks. Amino acids can link together to form long chains, typically a protein consists of 100 or more amino acids linked together. There are 20 different standard amino acids that your body requires for healthy function. These amino acids are often classified as essential and non-essential amino acids. Nonessential amino acids are amino acids that our bodies can produce even if we don’t get them from the food we eat. There are 11 non-essential amino acids (list). Essential amino acids cannot be made by the body, so, they must come from foods we eat. There are 9 essential amino acids. The basic structure of amino acids is that they consist of a alpha carbon, a carboxyl group, which is a carbon, oxygen, hydrogen, hydrogen group, a lone hydrogen atom, an amino group, which is a nitrogen, hydrogen, hydrogen group, and a side chain or functional group, which is often referred to as an R-group. The formation of the side chain is what makes amino acids different from one another. On the screen is the structural formulas for all 20 of the standard amino acids along with the amino acid selenocysteine, as some sources list it as a 21st standard amino acid. As you can see, they all have the same chemical backbone, and the only difference is their unique functional R group. These functional R groups of have chemical characteristics that allow amino acids to be organized into groups. Here we have the non polar amino acids, non polar meaning the electrons are shared equally in the molecule, these are hydrophobic, so they tend to be repelled from water. Here are the polar amino acids; these molecules can have interactions with other polar amino acids and with water molecules. Here are the charged amino acids, since they are charged, an ionic bond can form between an R group with a negative charge and an R group with a positive charge. And here are some amino acids that are considered to have unique structures. As was stated earlier, amino acids can link together to form long chains, there is an almost infinite number of different variations of chains that can be formed from amino acids. Each chain can have different characteristics with different chemical properties. When 2 amino acids join together they form what is called a peptide bond. A peptide bond is when the carboxyl or carbon, oxygen, hydrogen, hydrogen group of one amino acid bonds with the amino nitrogen, hydrogen, hydrogen group of another amino acid, as you can see here (on screen). This is done through a dehydration synthesis reaction, as the amino group involved in the bond loses a hydrogen atom, and the carboxyl group involved in the bond loses an oxygen and hydrogen. So, the peptide bonding results in the release of a water h2o molecule. More amino acids can link in, again releasing water molecules, and form what is called a polypeptide chain. As you can see in this polypeptide chain, at one end, an amino group remains, called the N terminal, and at the other end a carboxyl group remains, the C terminal. Typically a protein consists of 100 or more amino acids linked together. Some proteins are single polypeptide chains, and other proteins have polypeptide chains linked together. Individual amino acids can also be released from a peptide chain, by the decomposition reaction hydrolysis. In hydrolysis, a water molecule is added, breaking the peptide bond and freeing up amino acids. So, amino acids link together in a variety of sequences to form different types of proteins. Some of these proteins serve as enzymes, which help speed up metabolic reactions in the body, some serve as hormones and help regulate certain functions in the body, some proteins help form the structure of various tissues in the body, these are just a few of the many, many functions that proteins have in the body.
Views: 5931 Whats Up Dude
Bonds in Protein Structure
 
07:17
Types of Bond in Protein Structure http://www.biologyexams4u.com/2014/03/bond-used-in-protein-structure.html Protein Structure http://www.biologyexams4u.com/2011/10/protein-structure.html Stability of Proteins - Bonds Involved http://www.biologyexams4u.com/2013/01/protein-stability.html Multiple Choice Quiz on Protein Structure http://www.quizbiology.com/2013/05/biochemistry-quiz-on-protein-structure.html Difference between DNA and Protein http://www.majordifferences.com/2018/01/difference-between-dna-and-protein-dna-vs-protein.html
Views: 19140 biologyexams4u
More Peptide bond formation and Amino Acid structure problems
 
11:22
This video includes a basic discussion of the peptide bond. The video also includes one sample problem, which show potential exam style questions involving a drawing of a tetrapeptide, what would happen if the PH were increased, a London dispersion forces question, Hydrogen bonding between Histidine and threonine, Gibbs free energy question, and a question involving the range over which a buffer is useful.
Views: 17555 FortuneFavorsPrep
Peptide bond formation and relation to 3D structure
 
07:04
In this video I describe the reason we see regular secondary structures such as the alpha helix and Beta sheet.
Views: 16949 FortuneFavorsPrep
Amino Acids 7. The alpha helix secondary structure of Proteins
 
02:55
Top Tutors for all Subjects at all Levels here: https://spires.co/franklychemistry This video looks in detail at the alpha helix secondary structure of proteins. It uses animation to show intramolecular hydrogen bonds forming between the N-H of one amino acid and the C=O of another further along the chain. These bonds explain why the polypeptide should take on a twisted structure and maintain it. This is one in a series of videos looking at the chemistry of amino acids and proteins. Other in the series look at: the structures of amino acids; the zwitterion and its amphoteric properties; the reactions of the amino acid glycine (2-aminoethanoic acid) with sodium hydroxide, sodium carbonate and aqueous copper (II) sulfate solution; formation of two different dipeptides by the condensation reactions of glycine and alanine; formation of the backbone structure of a polypeptide; fibrous proteins verses globular proteins; protein hydrolysis
Views: 13881 FranklyChemistry
Protein Structure - Primary - Secondary - Tertiary - Quaternary - Structure of Protein
 
03:28
Check out the following links below! Over 1000+ Medical Questions: http://www.5minuteschool.com DONATE + SUPPORT US: http://paypal.me/5minuteschool Patreon: https://goo.gl/w841fz Follow us on Twitter: http://twitter.com/5MinuteSchool Follow us on Instagram: http://instagram.com/5minuteschool My personal Instagram: http://instagram.com/shahzaebb Contact us: [email protected] ______ This video looks into the different structures of proteins. We compare the structure of primary, secondary, tertiary and quaternary proteins. Diagrams are also included to help understand the key differences between these types of proteins at different levels. ◅ Donate: http://www.5minuteschool.com/donate ◅ Website: htttp://www.5minuteschool.com ◅ Twitter: http://www.twitter.com/5minuteschool ◅ Facebook: http://www.facebook.com/5minuteschool ◅ Email: [email protected]
Views: 125425 5MinuteSchool
#04 Biochemistry Protein Primary/Secondary Structure Lecture for Kevin Ahern's BB 450/550
 
48:58
1. Contact me at [email protected] / Friend me on Facebook (kevin.g.ahern) 2. Download my free biochemistry book at http://www.davincipress.com/freeforall.html 3. Take my free iTunes U course at https://itunes.apple.com/us/course/biochemistry/id556410409 4. Lecturio videos for medical students - https://www.lecturio.com/medical-courses/biochemistry.course 5. Course video channel at http://www.youtube.com/user/oharow/videos?view=1 6. Check out all of my free workshops at http://oregonstate.edu/dept/biochem/ahern/123.html 7. Check out my Metabolic Melodies at http://www.davincipress.com/ 8. My courses can be taken for credit (wherever you live) via OSU's ecampus. For details, see http://ecampus.oregonstate.edu/soc/ecatalog/ecourselist.htm?termcode=all&subject=BB 9. Course materials at http://davincipress.com/bb450.html Protein Structure II 1.The sequence of amino acids in a protein is ultimately responsible for all of the properties a protein has. The sequence of amino acids of a protein is referred to as its primary structure. 2. Peptide bonds form resonance structures such that the bond itself behaves like a double bond. Double bonds cannot rotate (unlike single bonds) and thus they define a plane. Alpha carbons on either side of a peptide bond are generally arranged in a trans configuration (about 10,000 trans to one cis), except when proline is involved. Peptide bonds involving proline favor the trans by about a 100 to 1 ratio. 3. The bonds around the alpha carbon (the carbon bonded to both an amino group and a carboxy group) can both rotate, however, because they are single bonds. One can thus describe a polypeptide as a series of planes separated by an alpha carbon, with the planes each being rotated a certain number of degrees relative to the alpha carbon. If we think of the alpha carbon as being in between two planes, then the plane on the left can rotate (theoretically) 360 degrees and the plane on the right can also theoretically rotate 360 degrees. These angles of rotation of planes are referred to as phi and psi angles. Phi refers to the rotational angle around the single bond between the alpha amino group and the alpha carbon. Psi refers to the rotational angle around the single bond between the alpha carbon and the alpha carboxyl group. 4. Ramachandran, recognized that not all rotations of phi and psi would be theoretically feasible because steric hindrance would preclude some rotational positions. He plotted theoretical rotations of psi versus phi and calculated which of these angles would provide stable structures. The regions of stability turn out to be regions of known stability from protein structures that have been determined. 5. The secondary structure of a polypeptide refers to regular/repeating structure(s) arising from interactions between amino acids that are relatively close together in primary sequence. This means less than 10 amino acids away. 6. One protein secondary structure that is stable in both real proteins and theoretical ones (Ramachandran plots) is the alpha helix. Alpha helices are one type of secondary structure and form coils. 7. Hydrogen bonds are primary forces stabilizing secondary structures. In alpha helices, carbonyl oxygen from a peptide bond forms a hydrogen bond with an amine nitrogen of another peptide bond four amino acids distant. 8. Certain amino acids with simple side chains, such as alanine, are very favorable for formation of alpha helices, whereas bulky (tryptophan) or cyclic (proline) amino acids tend to disrupt alpha helices. . 9. Another type of common secondary structure commonly found in protein is the beta strand (note that the term beta sheet refers to layering together of beta strands together), which consists of amino acid backbones in a V shape (like the pleats of a drape). A beta strand can be thought of as a helix in two dimensions. 10. Beta sheets arise from arrangement of beta strands. These arise from interactions (hydrogen bonds) between beta strands (parallel or antiparallel), such that the carbonyl oxygen of one side interacts with the amine hydrogen with the other. 11. Essential features of proteins that are essential for their overall structure are turns. Turns interrupt secondary structure (alpha helices and beta strands) and often involve proline and glycine residues. 12. Another type of fibrous protein is collagen, the most abundant protein in your body. It contains three intertwined helices comprised of abundant repeating units of glycine, proline, and hydroxylproline 13. Hydroxylation of proline is a post-translational modification (occurs after the protein is made) and the hydroxyls are placed there in a reaction that uses vitamin C. 14. The hydroxyls of hydroxyproline can react with other, forming covalent cross-links that make the collagen fibers more sturdy.
Views: 53764 Kevin Ahern
Peptide bond
 
06:16
This lecture explains about peptide bond formation and about the ramachandran plot and protein structure analysis of the peptide bonds. A peptide bond is a chemical bond shaped between two molecules when the carboxyl crew of 1 molecule reacts with the amino team of the opposite molecule, releasing a molecule of water (H2O). This can be a dehydration synthesis reaction (often referred to as a condensation reaction), and most often happens between amino acids. The ensuing CO-NH bond is known as a peptide bond, and the resulting molecule is an amide. The four-atom functional group -C(=O)NH- is referred to as an amide team or (in the context of proteins) a peptide crew. Polypeptides and proteins are chains of amino acids held together via peptide bonds, as is the backbone of PNA. For more information, log on to- http://www.shomusbiology.com/ Get Shomu's Biology DVD set here- http://www.shomusbiology.com/dvd-store/ Download the study materials here- http://shomusbiology.com/bio-materials.html Remember Shomu’s Biology is created to spread the knowledge of life science and biology by sharing all this free biology lectures video and animation presented by Suman Bhattacharjee in YouTube. All these tutorials are brought to you for free. Please subscribe to our channel so that we can grow together. You can check for any of the following services from Shomu’s Biology- Buy Shomu’s Biology lecture DVD set- www.shomusbiology.com/dvd-store Shomu’s Biology assignment services – www.shomusbiology.com/assignment -help Join Online coaching for CSIR NET exam – www.shomusbiology.com/net-coaching We are social. Find us on different sites here- Our Website – www.shomusbiology.com Facebook page- https://www.facebook.com/ShomusBiology/ Twitter - https://twitter.com/shomusbiology SlideShare- www.slideshare.net/shomusbiology Google plus- https://plus.google.com/113648584982732129198 LinkedIn - https://www.linkedin.com/in/suman-bhattacharjee-2a051661 Youtube- https://www.youtube.com/user/TheFunsuman Thank you for watching
Views: 29801 Shomu's Biology
Protein Folding Mechanism
 
07:48
Protein folding is the physical process by which a protein chain acquires its native 3-dimensional structure, a conformation that is usually biologically functional, in an expeditious and reproducible manner. It is the physical process by which a polypeptide folds into its characteristic and functional three-dimensional structure from random coil. Each protein exists as an unfolded polypeptide or random coil when translated from a sequence of mRNA to a linear chain of amino acids. This polypeptide lacks any stable (long-lasting) three-dimensional structure (the left hand side of the first figure). As the polypeptide chain is being synthesized by the ribosome, the linear chain begins to fold into its three dimensional structure. Folding begins to occur even during translation of the polypeptide chain. Amino acids interact with each other to produce a well-defined three-dimensional structure, the folded protein (the right hand side of the figure), known as the native state. The resulting three-dimensional structure is determined by the amino acid sequence or primary structure (Anfinsen's dogma).[2] The energy landscape describes the folding pathways in which the unfolded protein is able to assume its native state. Experiments beginning in the 1980s indicate the codon for an amino acid can also influence protein structure. The correct three-dimensional structure is essential to function, although some parts of functional proteins may remain unfolded, so that protein dynamics is important. Failure to fold into native structure generally produces inactive proteins, but in some instances misfolded proteins have modified or toxic functionality. Several neurodegenerative and other diseases are believed to result from the accumulation of amyloid fibrils formed by misfolded proteins. Many allergies are caused by incorrect folding of some proteins, because the immune system does not produce antibodies for certain protein structures. Primary Structure : The primary structure of a protein, its linear amino-acid sequence, determines its native conformation.[7] The specific amino acid residues and their position in the polypeptide chain are the determining factors for which portions of the protein fold closely together and form its three dimensional conformation. The amino acid composition is not as important as the sequence.[8] The essential fact of folding, however, remains that the amino acid sequence of each protein contains the information that specifies both the native structure and the pathway to attain that state. This is not to say that nearly identical amino acid sequences always fold similarly.[9] Conformations differ based on environmental factors as well; similar proteins fold differently based on where they are found. Secondary Structure: Formation of a secondary structure is the first step in the folding process that a protein takes to assume its native structure. Characteristic of secondary structure are the structures known as alpha helices and beta sheets that fold rapidly because they are stabilized by intramolecular hydrogen bonds, as was first characterized by Linus Pauling. Formation of intramolecular hydrogen bonds provides another important contribution to protein stability. Alpha helices are formed by hydrogen bonding of the backbone to form a spiral shape (refer to figure on the right).The beta pleated sheet is a structure that forms with the backbone bending over itself to form the hydrogen bonds (as displayed in the figure to the left). The hydrogen bonds are between the amide hydrogen and carbonyl carbon of the peptide bonds. Tertiary Structure The alpha helices and beta pleated sheets can be amphipathic in nature, or contain a hydrophilic portion and a hydrophobic portion. This property of secondary structures aids in the tertiary structure of a protein in which the folding occurs so that the hydrophilic sides are facing the aqueous environment surrounding the protein and the hydrophobic sides are facing the hydrophobic core of the protein.[11] Secondary structure hierarchically gives way to tertiary structure formation. Once the protein's tertiary structure is formed and stabilized by the hydrophobic interactions, there may also be covalent bonding in the form of disulfide bridges formed between two cysteine residues. Tertiary structure of a protein involves a single polypeptide chain; however, additional interactions of folded polypeptide chains give rise to quaternary structure formation. Chaperone Concept : The Chaperones assist in the correct folding pattern of a protein.If Chaperone fails to do so then Protein ultimately becomes Prion protein which gives rise to several diseases lile Kuru , Scrapie disease and Alziemers.
Views: 22390 Hussain Biology
#5 Biochemistry Lecture (Protein Structure) from Kevin Ahern's BB 350
 
49:20
1. Contact me at [email protected] / Friend me on Facebook (kevin.g.ahern) 2. Download my free biochemistry book at http://biochem.science.oregonstate.edu/biochemistry-free-and-easy 3. Take my free iTunes U course at https://itunes.apple.com/us/course/biochemistry/id556410409 4. Check out my free book for pre-meds at http://biochem.science.oregonstate.edu/biochemistry-free-and-easy 5. Course video channel at http://www.youtube.com/user/oharow/videos?view=1 6. Check out all of my free workshops at http://www.youtube.com/playlist?list=PLlnFrNM93wqyTiCLZKehU1Tp8rNmnOWYB&feature=view_all 7. Check out my Metabolic Melodies at http://www.davincipress.com/metabmelodies.html 8. Take my courses for credit (wherever you live) via OSU's ecampus. For details, see http://ecampus.oregonstate.edu/soc/ecatalog/ecourselist.htm?termcode=all&subject=BB 9. Course materials at http://oregonstate.edu/instruct/bb350 Lecture Highlights Protein Structure 1. Peptide bonds are the covalent bonds that join together individual amino acids within a protein. They are formed in a reaction in the ribosome in which the carboxyl group of one amino acid is joined to the amino end of another amino acid. Proteins always have a free alpha amino end and a free alpha carboxyl end. 2. Interesting molecules made from or containing amino acids include histamine (involved in allergies), nutrasweet (artificial sweetener made of aspartic acid and phenylalanine), and glutathione (cellular antioxidant). 3. Calculating the charge on a polypeptide is simple. One simply tallies the charge of the alpha carboxyl group, the alpha amino group, and all of the R groups. Note that the internal carboxyl/amino groups are destroyed in making the peptide bond. 4. Peptide bonds act like double bonds due to electronic resonance. 5. Primary structure of a polypeptide corresponds to the sequence of amino acids comprising it. Every property of a protein ultimately traces to the primary structure of a protein. As the primary structure changes, so too does the nature of what the protein can do changes. 6. Secondary structure arises from interactions between amino acids close to each other (within 10) in primary sequence. Alpha helices are common secondary structures in polypeptides. Alpha helices are stabilized by hydrogen bonds between the oxygen of a carbonyl group and a hydrogen on the amide four amino acids away. Forces that destabilize hydrogen bonds also destabilize alpha helices. Heat is one such force that destabilizes alpha helices. Soap is another. 7. Beta strands are other protein secondary structures. When aligned in multiple units, beta strands are referred to as beta sheets. The forces holding the strand together are hydrogen bonds. 8. Both alpha helices and beta sheets were discovered by the most famous scientist ever to graduate from OSU, Dr. Linus Pauling. 9. Fibrous proteins, such as the keratin of your hair, contain almost exclusively primary and secondary structure, but no tertiary or quaternary structure. Examples include keratin (hair, nails) and collagen. Proteins that 'fold' into glob-like structures are known as globular proteins. Globular proteins are far more common than fibrous proteins. 10. Globular proteins have a folded structure arising from turns between regions of secondary structure. Tertiary structure arises from interactions between amino acids that are NOT close in primary structure. 11. Turns are critically important for determining the overall three-dimensional structure of a protein. Turns occur over about a distance of 4 amino acids and involve amino acids with bulky or inflexible side chains. A common component of turns is the amino acid proline. 12. The following forces stabilize protein structure Primary = peptide bonds (covalent) Secondary = hydrogen bonds Tertiary = hydrogen bonds, ionic interactions, hydrophobic interactions, covalent (disulfide) bonds, ionic interactions 13. Proteins can have many regions of alpha helix and beta sheets within them. The overall 3D structure of a protein is a function of how all of them are arranged together. 14. Globular proteins have many folds and turns than arrange the helices and sheets into unusual patterns. The process whereby the protein assumes is final shape is called 'folding.' 15. Globular proteins that are soluble in water usually have their polar amino acids on the outside in contact with water and their non-polar amino acids on the inside associating with each other (thus avoiding water). 16. Disruption of forces that stabilize protein structure cause folded proteins to unfold. Unfolded proteins are not functional. We describe them as denatured. Denaturing agents include heat, detergent, acid or base.
Views: 21432 Kevin Ahern
Introduction to amino acids | Macromolecules | Biology | Khan Academy
 
09:54
Understanding amino acids and their role in the Central Dogma of Molecular Biology (how the information in DNA eventually gets expressed as chains of amino acids). Thinking about the amino and carboxyl groups and how amino acids are typically found as zwitterions at physiological pH. How amino acid side chains can impact protein structure. Watch the next lesson: https://www.khanacademy.org/science/biology/macromolecules/proteins-and-amino-acids/v/peptide-bond-formation?utm_source=YT&utm_medium=Desc&utm_campaign=biology Missed the previous lesson? https://www.khanacademy.org/science/biology/macromolecules/nucleic-acids/v/molecular-structure-of-rna?utm_source=YT&utm_medium=Desc&utm_campaign=biology Biology on Khan Academy: Life is beautiful! From atoms to cells, from genes to proteins, from populations to ecosystems, biology is the study of the fascinating and intricate systems that make life possible. Dive in to learn more about the many branches of biology and why they are exciting and important. Covers topics seen in a high school or first-year college biology course. About Khan Academy: Khan Academy offers practice exercises, instructional videos, and a personalized learning dashboard that empower learners to study at their own pace in and outside of the classroom. We tackle math, science, computer programming, history, art history, economics, and more. Our math missions guide learners from kindergarten to calculus using state-of-the-art, adaptive technology that identifies strengths and learning gaps. We've also partnered with institutions like NASA, The Museum of Modern Art, The California Academy of Sciences, and MIT to offer specialized content. For free. For everyone. Forever. #YouCanLearnAnything Subscribe to Khan Academy's Biology channel: https://www.youtube.com/channel/UC82qE46vcTn7lP4tK_RHhdg?sub_confirmation=1 Subscribe to Khan Academy: https://www.youtube.com/subscription_center?add_user=khanacademy
Views: 261333 Khan Academy
Protein Structure and Folding
 
07:46
After a polypeptide is produced in protein synthesis, it's not necessarily a functional protein yet! Explore protein folding that occurs within levels of protein structure with the Amoeba Sisters! Primary, secondary, tertiary, and quaternary protein structure levels are briefly discussed. Video also mentions chaperonins (chaperone proteins) and how proteins can be denatured. Table of Contents: 0:41 Reminder of Protein Roles 1:06 Modifications of Proteins 1:25 Importance of Shape for Proteins 1:56 Levels of Protein Structure 2:06 Primary Structure 3:10 Secondary Structure 3:45 Tertiary Structure 4:58 Quaternary Structure [not in all proteins] 6:01 Proteins often have help in folding [introduces chaperonins] 6:40 Denaturing Proteins *Further Reading Suggestions* Related to Protein Misfoldings: https://www.nature.com/scitable/topicpage/protein-misfolding-and-degenerative-diseases-14434929 https://www.scientificamerican.com/article/misfolded-proteins-travel-in-huntington-s-disease/ Learn About "The Protein Folding Problem": https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2443096/ Factual References: OpenStax, Biology. OpenStax CNX. Jun 1, 2018 http://cnx.org/contents/[email protected] Reece, J. B., & Campbell, N. A. (2011). Campbell biology. Boston: Benjamin Cummings / Pearson. Support us on Patreon! http://www.patreon.com/amoebasisters More ways to Support Us? http://www.amoebasisters.com/support-us.html Our Resources: Biology Playlist: https://www.youtube.com/playlist?list=PLwL0Myd7Dk1F0iQPGrjehze3eDpco1eVz GIFs: http://www.amoebasisters.com/gifs.html Handouts: http://www.amoebasisters.com/handouts.html Comics: http://www.amoebasisters.com/parameciumparlorcomics Unlectured Series: https://www.amoebasisters.com/unlectured Connect with us! Website: http://www.AmoebaSisters.com Twitter: http://www.twitter.com/AmoebaSisters Facebook: http://www.facebook.com/AmoebaSisters Tumblr: http://www.amoebasisters.tumblr.com Pinterest: http://www.pinterest.com/AmoebaSister­s Instagram: https://www.instagram.com/amoebasistersofficial/ Visit our Redbubble store at http://www.amoebasisters.com/store The Amoeba Sisters videos demystify science with humor and relevance. The videos center on Pinky's certification and experience in teaching science at the high school level. Pinky's teacher certification is in grades 4-8 science and 8-12 composite science (encompassing biology, chemistry, and physics). Amoeba Sisters videos only cover concepts that Pinky is certified to teach, and they focus on her specialty: secondary life science. For more information about The Amoeba Sisters, visit: http://www.amoebasisters.com/about-us.html We cover the basics in biology concepts at the secondary level. If you are looking to discover more about biology and go into depth beyond these basics, our recommended reference is the FREE, peer reviewed, open source OpenStax biology textbook: https://openstax.org/details/books/biology Our intro music designed and performed by Jeremiah Cheshire. End music is this video is listed free to use/no attribution required from the YouTube audio library https://www.youtube.com/audiolibrary/music?feature=blog We take pride in our AWESOME community, and we welcome feedback and discussion. However, please remember that this is an education channel. See YouTube's community guidelines https://www.youtube.com/yt/policyandsafety/communityguidelines.html and YouTube's policy center https://support.google.com/youtube/topic/2676378?hl=en&ref_topic=6151248. We also reserve the right to remove comments with vulgar language. We have YouTube's community contributed subtitles feature on to allow translations for different languages, and we are thankful for those that contribute different languages! YouTube automatically credits the different language contributors below (unless the contributor had opted out of being credited). We are not affiliated with any of the translated subtitle credits that YouTube may place below. If you have a concern about community contributed contributions, please contact us.
Views: 16772 Amoeba Sisters
Protein Structure (Part 1 of 4) - Levels of Protein Structure
 
19:47
Moof's Medical Biochemistry Video Course: http://moof-university.thinkific.com/courses/medical-biochemistry-for-usmle-step-1-exam For Related Practice Problems with Worked Video Solutions on Protein Structure and Function, visit courses.moofuniversity.com. The four levels of protein structure EXPLAINED in this video! Primary structure of proteins describes the actual sequence of amino acids in a polypeptide; namely, it describes the order in which the amino acids are connection reading from the N (amino) terminus to the C (carboxy) terminus of a polypeptide. Two polypeptides (or proteins) can have the same amino acid contents, but if they are connected in different orders in the two polypeptides, the two polypeptides will end up folding in different ways and yield different structures. It's often said that, because of this idea, the primary structure of a protein determines its overall 3D structure. Secondary structure of proteins describes the ordered patterns of 3D arrangements on localized regions of the BACKBONE of the polypeptide. The word BACKBONE is particularly important, as it implies the repeating N-C-C units of each amino acid, and specifically the interactions between the components of said backbone, the carbonyl and amide. It is often mentioned that the interactions that hold secondary structure together are hydrogen bonds, which is, of course, true. It is also mentioned that secondary structure consists of alpha helices and beta pleated sheets are the actual secondary structures held together by said hydrogen bonds. That's also true. It must be specifically noted, though, that the hydrogen bonds that hold together the alpha helices and beta pleated sheets are the hydrogen bonds between the carbonyl oxygen and the amide hydrogen of the backbone. This does NOT include any other hydrogen bonds (like those that hold together side chains), which brings me to .... Tertiary structure of proteins is often describe simply as the overall 3D arrangement of a polypeptide after folding. That's hardly it. Tertiary structure further includes the interactions between and among the side chains of the amino acids, as well as the interactions between and among secondary structures. Prosthetic groups, which are non amino acid components of proteins, that are a part of a protein's overall structure, are included in tertiary structure as well. The different types of interactions between side chains include the noncovalent interactions (hydrophobic interactions, hydrogen bonds, and electrostatic interactions) as well as a specific type of covalent interaction (disulfide bonds / disulfide bridges). All are important components of a protein's tertiary structure. Quaternary structure of proteins simply describes the idea that multiple polypeptide chains can come together and form a multi-subunit protein. If and when this happens, it is classified as quaternary structure. For a suggested viewing order of the videos, information on tutoring, personalized video solutions, and an opportunity to support Moof University financially, visit MoofUniversity.com, and follow Moof University on the different social media platforms. Don't forget to LIKE, COMMENT, and SUBSCRIBE: http://www.youtube.com/subscription_center?add_user=MoofUniversity SUPPORT MOOF UNIVERSITY: http://www.moofuniversity.com/support-moof/ BUY A T-SHIRT https://shop.spreadshirt.com/moofuniversity/ INFORMATION ABOUT TUTORING AND PERSONALIZED VIDEO SOLUTIONS: http://www.moofuniversity.com/tutoring/ INSTAGRAM: https://instagram.com/moofuniversity/ FACEBOOK: https://www.facebook.com/pages/Moof-University/1554858934727545 TWITTER: https://twitter.com/moofuniversity
Views: 60083 Moof University
Protein Structure (Part 2 of 4) - Secondary Structure - Alpha Helix
 
13:38
Moof's Medical Biochemistry Video Course: http://moof-university.thinkific.com/courses/medical-biochemistry-for-usmle-step-1-exam For Related Practice Problems with Worked Video Solutions on Protein Structure and Function, visit courses.moofuniversity.com. In this video, I explain the details of the alpha helix (alpha helices). The alpha helix is an important type of secondary protein structure. The alpha helix is, specifically, a right handed helix held together by hydrogen bonds (H-bonds) between the carbonyl oxygen and amide hydrogen of the polypeptide backbone. These hydrogen bonds are parallel to the axis of the helix, and they exist between every 4th amino acid of the backbone. The side chains of the amino acids (R-groups) extend out of the helix, running perpendicular to the axis of the helix. The alpha helix is often thought of as having polarity, with the N-terminus (amino terminus) having a partial positive charge, while the C-terminus (carboxy terminus) carries a partial negative charge. There are a few things that can disrupt or damage and alpha helix: 1. Proline – Proline’s side chain is wrapped around and connected to its alpha amino group. This restricts rotation that is necessary to form the particular structure of the alpha helix. Also, when proline’s amino group is part of a peptide bond, it has no hydrogen on it that can hydrogen bond. In short, substituting a proline in for an amino acid that is part of an alpha helix will ruin the alpha helix’s structure. 2. Electrostatic Repulsions between Side Chains with Like Charges – If the R groups of the amino acids that extend outward from the alpha helix happen to be next to each other with like charges, they can repel each other and bend the helix in a way that compromises its structure. For instance, if two negatively charged aspartate side chains are next to each other, they will repel. Likewise, this could occur with two positively charged arginine side chains. 3. Steric Hindrance – The alpha helix is a fairly tightly packed helix, and amino acids with bulky side chains can disrupt its structure by taking up too much space being next to each in the peptide chain that makes up the helix. For example, two phenylalanine side chains next to each other means two aromatic rings (bulky) next to each other. This could disrupt the alpha helix. For a suggested viewing order of the videos, information on tutoring, personalized video solutions, and an opportunity to support Moof University financially, visit MoofUniversity.com, and follow Moof University on the different social media platforms. Don't forget to LIKE, COMMENT, and SUBSCRIBE: http://www.youtube.com/subscription_center?add_user=MoofUniversity SUPPORT MOOF UNIVERSITY: http://www.moofuniversity.com/support-moof/ BUY A T-SHIRT https://shop.spreadshirt.com/moofuniversity/ INFORMATION ABOUT TUTORING AND PERSONALIZED VIDEO SOLUTIONS: http://www.moofuniversity.com/tutoring/ INSTAGRAM: https://instagram.com/moofuniversity/ FACEBOOK: https://www.facebook.com/pages/Moof-University/1554858934727545 TWITTER: https://twitter.com/moofuniversity
Views: 75172 Moof University
Overview of protein structure | Macromolecules | Biology | Khan Academy
 
09:58
Primary, secondary, tertiary and quaternary protein structure. Thinking about how the different factors impacting a protein's structure. Beta pleated sheets. Alpha helices. Watch the next lesson: https://www.khanacademy.org/science/biology/macromolecules/proteins-and-amino-acids/v/tertiary-structure-of-proteins?utm_source=YT&utm_medium=Desc&utm_campaign=biology Missed the previous lesson? https://www.khanacademy.org/science/biology/macromolecules/proteins-and-amino-acids/v/peptide-bond-formation?utm_source=YT&utm_medium=Desc&utm_campaign=biology Biology on Khan Academy: Life is beautiful! From atoms to cells, from genes to proteins, from populations to ecosystems, biology is the study of the fascinating and intricate systems that make life possible. Dive in to learn more about the many branches of biology and why they are exciting and important. Covers topics seen in a high school or first-year college biology course. About Khan Academy: Khan Academy offers practice exercises, instructional videos, and a personalized learning dashboard that empower learners to study at their own pace in and outside of the classroom. We tackle math, science, computer programming, history, art history, economics, and more. Our math missions guide learners from kindergarten to calculus using state-of-the-art, adaptive technology that identifies strengths and learning gaps. We've also partnered with institutions like NASA, The Museum of Modern Art, The California Academy of Sciences, and MIT to offer specialized content. For free. For everyone. Forever. #YouCanLearnAnything Subscribe to Khan Academy's Biology channel: https://www.youtube.com/channel/UC82qE46vcTn7lP4tK_RHhdg?sub_confirmation=1 Subscribe to Khan Academy: https://www.youtube.com/subscription_center?add_user=khanacademy
Views: 189112 Khan Academy
Peptide bond formation and Amino Acid structure problem
 
06:29
This video includes a basic discussion of the peptide bond. The video also includes one sample problem, which shows a potential exam style questions involving a drawing of a tetrapeptide.
Views: 38307 FortuneFavorsPrep
Amino Acids 12. Protein Hydrolysis.
 
04:35
Top Tutors for all Subjects at all Levels here: https://spires.co/franklychemistry This video uses animation to illustrate and explain during the hydrolysis of a protein. Hydrolysis means to break a molecule apart using the elements of water. It can be done by either refluxing the protein with 6 Molar Hydrochloric acid for 24 hours or leaving the protein mixed with protease enzymes at 37 Celsius ffor several hours. Protein hydrolysis is relatively difficult because they have a complex structure. The primary and secondary structures must be broken apart, while the primary, secondary, tertiary and quarternary structures must be broken apart. There are at least 5 kinds of bonds to be broken. These are peptide bonds holding the primary structure together, hydrogen bonds holding the twisted secondary structure together and more hydrogen bonds, plus van der Waals forces, electrostatic attractions and disulphide bonds holding the tertiary and quarternary structures together.
Views: 7478 FranklyChemistry
Protein structure | primary secondary tertiary and  quaternary structure of protein
 
10:31
Protein structure - This lecture explains about the protein structure hierarchy including primary, secondary, tertiary structures of protein. All the types of protein structures are explained in this video with example. So watch this video to understand alpha helix and beta sheet structure and the role of primary structure of the protein to make 3d protein which dictates the function of the protein. So keep watching this video for knowing the following details 1. Primary structure of protein 2. Secondary structure of protein 3. Tertiary structure of the protein For more information, log on to- http://www.shomusbiology.com/ Get Shomu's Biology DVD set here- http://www.shomusbiology.com/dvd-store/ Download the study materials here- http://shomusbiology.com/bio-materials.html Remember Shomu’s Biology is created to spread the knowledge of life science and biology by sharing all this free biology lectures video and animation presented by Suman Bhattacharjee in YouTube. All these tutorials are brought to you for free. Please subscribe to our channel so that we can grow together. You can check for any of the following services from Shomu’s Biology- Buy Shomu’s Biology lecture DVD set- www.shomusbiology.com/dvd-store Shomu’s Biology assignment services – www.shomusbiology.com/assignment -help Join Online coaching for CSIR NET exam – www.shomusbiology.com/net-coaching We are social. Find us on different sites here- Our Website – www.shomusbiology.com Facebook page- https://www.facebook.com/ShomusBiology/ Twitter - https://twitter.com/shomusbiology SlideShare- www.slideshare.net/shomusbiology Google plus- https://plus.google.com/113648584982732129198 LinkedIn - https://www.linkedin.com/in/suman-bhattacharjee-2a051661 Youtube- https://www.youtube.com/user/TheFunsuman Thank you for watching the video lecture on protein structure.
Views: 104956 Shomu's Biology
Tertiary structure of proteins | Macromolecules | Biology | Khan Academy
 
07:28
How side chain interactions can impact the tertiary structure of proteins. Watch the next lesson: https://www.khanacademy.org/science/biology/structure-of-a-cell/introduction-to-cells/v/scale-of-cells?utm_source=YT&utm_medium=Desc&utm_campaign=biology Missed the previous lesson? https://www.khanacademy.org/science/biology/macromolecules/proteins-and-amino-acids/v/overview-of-protein-structure?utm_source=YT&utm_medium=Desc&utm_campaign=biology Biology on Khan Academy: Life is beautiful! From atoms to cells, from genes to proteins, from populations to ecosystems, biology is the study of the fascinating and intricate systems that make life possible. Dive in to learn more about the many branches of biology and why they are exciting and important. Covers topics seen in a high school or first-year college biology course. About Khan Academy: Khan Academy offers practice exercises, instructional videos, and a personalized learning dashboard that empower learners to study at their own pace in and outside of the classroom. We tackle math, science, computer programming, history, art history, economics, and more. Our math missions guide learners from kindergarten to calculus using state-of-the-art, adaptive technology that identifies strengths and learning gaps. We've also partnered with institutions like NASA, The Museum of Modern Art, The California Academy of Sciences, and MIT to offer specialized content. For free. For everyone. Forever. #YouCanLearnAnything Subscribe to Khan Academy's Biology channel: https://www.youtube.com/channel/UC82qE46vcTn7lP4tK_RHhdg?sub_confirmation=1 Subscribe to Khan Academy: https://www.youtube.com/subscription_center?add_user=khanacademy
Views: 96238 Khan Academy
Nucleic acids - DNA and RNA structure
 
11:16
Nucleic acids DNA and RNA structure LIKE US ON FACEBOOK : https://fb.me/Medsimplified Nucleic acids are biopolymers, or small biomolecules, essential to all known forms of life. They are composed of monomers, which are nucleotides made of three components: a 5-carbon sugar, a phosphate group and a nitrogenous base. If the sugar is a simple ribose, the polymer is RNA (ribonucleic acid); if the sugar is derived from ribose as deoxyribose, the polymer is DNA (deoxyribonucleic acid). Nucleic acids are the most important of all biomolecules. They are found in abundance in all living things, where they function to create and encode and then store information in the nucleus of every living cell of every life-form organism on Earth. In turn, they function to transmit and express that information inside and outside the cell nucleus—to the interior operations of the cell and ultimately to the next generation of each living organism. The encoded information is contained and conveyed via the nucleic acid sequence, which provides the 'ladder-step' ordering of nucleotides within the molecules of RNA and DNA. Strings of nucleotides are bonded to form helical backbones—typically, one for RNA, two for DNA—and assembled into chains of base-pairs selected from the five primary, or canonical, nucleobases, which are: adenine, cytosine, guanine, thymine, and uracil; note, thymine occurs only in DNA and uracil only in RNA. Using amino acids and the process known as protein synthesis,[3] the specific sequencing in DNA of these nucleobase-pairs enables storing and transmitting coded instructions as genes. In RNA, base-pair sequencing provides for manufacturing new proteins that determine the frames and parts and most chemical processes of all life forms. One DNA or RNA molecule differs from another primarily in the sequence of nucleotides. Nucleotide sequences are of great importance in biology since they carry the ultimate instructions that encode all biological molecules, molecular assemblies, subcellular and cellular structures, organs, and organisms, and directly enable cognition, memory, and behavior (See: Genetics). Enormous efforts have gone into the development of experimental methods to determine the nucleotide sequence of biological DNA and RNA molecules,[26][27] and today hundreds of millions of nucleotides are sequenced daily at genome centers and smaller laboratories worldwide Watch Again : https://youtu.be/0lZRAShqft0
Views: 100512 MEDSimplified
Protein Shape - Levels Of Protein Structure - Shape Of Proteins - What Is Protein Denaturation
 
02:06
In this video we discuss the 4 different levels of protein shape, as we cover primary, secondary, tertiary or the third level, and quaternary or the fourth level. We also discuss the denaturation of protein and some things that cause it. Protein shape There are 4 different levels of protein structure, or protein shape. Primary, secondary, tertiary or the third level, and quaternary or the fourth level. The primary or 1st level of protein structure is a chain like or linear sequence of amino acids joined by peptide bonds as you see here. The secondary or 2nd level has 2 shapes, an alpha helix or coil like formation, or folded pattern called a beta sheet. In both of these structures hydrogen bonds between the R groups of the amino acids stabilize the shape of the protein. The tertiary or 3rd level of protein structure involves more folding and bonding of the secondary structure. The coils may even touch each other as some covalent bonds form from the sharing of electrons between different amino acids, but most of these twists and folds occur from the result of ionic bonds between positively and negatively charged r groups of amino acids. The quaternary or 4th level is where clusters of more than one polypeptide chain link together to form a giant molecule. Many different types of bonds may be formed within this structure. The shape of a protein is important, for instance, fibrous proteins are extended linear proteins that are part of ligaments, tendons and muscles, and globular proteins fold into almost spherical shapes and have their hydrophobic or water fearing r groups buried deep within the core, and their hydrophilic or water loving r groups extended out into the water when in an aqueous environment. Proteins take their shape based on the job they are required to perform and some have moving parts that are important to their functions. Proteins can have their structure or shaped by denaturation. When this happens, the protein is no longer able to carry out its job. Denaturation can take place because of change of temperature, change in pH, or in the presence of certain hazardous chemicals.
Views: 9519 Whats Up Dude
Amino Acids 5. Formation of a Polypeptide.
 
03:08
Top Tutors for all Subjects at all Levels here: https://spires.co/franklychemistry This video looks at the formation of a polypeptide in a condensation reaction. It uses animation to show amino acids reacting together to form a long chain polymer molecule. This is one in a series of videos looking at the chemistry of amino acids and proteins. Other in the series look at: the structures of amino acids; the zwitterion and its amphoteric properties; the reactions of the amino acid glycine (2-aminoethanoic acid) with sodium hydroxide, sodium carbonate and aqueous copper (II) sulfate solution; formation of two possible dipeptides by the condensation reactions of glycine and alanine; a general account of secondary structure; the alpha helix secondary structure; the beta-pleated sheet secondary structure; fibrous proteins verses globular proteins; protein hydrolysis
Views: 3331 FranklyChemistry
Proteins
 
09:16
Paul Andersen explains the structure and importance of proteins. He describes how proteins are created from amino acids connected by dehydration synthesis. He shows the importance of chemical properties in the R-groups of individual amino acids in the polypeptide. He explains the four levels of protein folding and gives you an opportunity to fold proteins of your own using the game Foldit: Download the video game foldit here: http://fold.it/portal/ Intro Music Atribution Title: I4dsong_loop_main.wav Artist: CosmicD Link to sound: http://www.freesound.org/people/CosmicD/sounds/72556/ Creative Commons Atribution License
Views: 863754 Bozeman Science
Amino Acids and Proteins: How to draw Alpha Amino Acids and Primary Structure of Proteins
 
09:20
Amino acids are the building blocks of proteins and the unique sequence of amino acids linked via peptide bonds to form a polypeptide chain will give the primary structure of proteins. Learn how to draw alpha amino acids and primary structure of proteins in this video lesson! Topic: Nitrogen Compounds, Organic Chemistry, JC, H2, A Level Chemistry, Singapore Found this video useful? Please LIKE this video and SHARE it with your friends. SUBSCRIBE to my YouTube Channel for new A Level H2 Chemistry video lessons every week! Any feedback, comments or questions to clarify? Suggestions for new video lessons? Drop them in the COMMENTS Section, I would love to hear from you! Do you know you can learn Chemistry Concepts under a minute? Follow me on Instagram for my weekly one-minute video lessons at https://www.instagram.com/chemistryguru/ I am also conducting JC H2 Chemistry classes at Bishan Central, Singapore. With my years of experience tutoring hundreds of JC students since 2010, I am confident that I can make H2 Chemistry Simpler for you too! For more information please visit https://chemistryguru.com.sg/ -~-~~-~~~-~~-~- Please watch my latest video: "Titration Curve for Weak Acid - Strong Base Reaction" https://www.youtube.com/watch?v=5iyDNuYzLz4 -~-~~-~~~-~~-~-
Protein Structure
 
07:20
Proteins have four distinctive levels of structure. 1.) Protein assembly is the primary structure which involves the amino acid sequence. 2.) Protein folding starts in the secondary structure with alpha helix and beta sheets being to secondary structure formations that occur as the result of hydrogen bonds. 3.) Tertiary structure is the final 3-dimentional shape of the protein. 4.) Quaternary structure involves the spatial arrangement of polypeptides in a multi-component protein. Chaperone proteins are protective hallow structures that help newly produced proteins to fold properly. Link to Lecture Slides: https://drive.google.com/open?id=1CSG9YnQnVa8nyGBO78WjhTKpp4CXwplt *Due to the description character limit the full work cited for "Protein Structure" can be viewed at... https://drive.google.com/open?id=1tcOWDzN5PJAfGGd0ejkQpxVwXL006oEg
Views: 45 DeBacco University
Amino Acids (Part 5 of 5) - Peptides, Polypeptides, and Peptide Bonds
 
20:11
Moof's Medical Biochemistry Video Course: http://moof-university.thinkific.com/courses/medical-biochemistry-for-usmle-step-1-exam For Related Practice Problems with Worked Video Solutions on Amino Acids, visit courses.moofuniversity.com. What are peptides and polypeptides and peptide bonds? Find out in this video! It is commonly mentioned that amino acids are the building blocks or monomers of proteins, which are, of course, polymers. Specifically, amino acids link between the alpha carboxylic acid group of the first amino acid and the alpha amino group of the next amino acid via dehydration synthesis, creating an amide bond that is specifically called a peptide bond. This covalent bond is fairly rigid and planar in structure due to its partial double bond character due to the resonating lone pair of electrons on the amide nitrogen. Rotation about this bond is restricted due to its planar nature. When two amino acids link via a peptide bond, it's called a dipeptide -- because two amino acids make up that structure. A tripeptide is three amino acids linked by peptide bonds. A peptide is the term associated with a short segment of a few amino acids connected by peptide bonds. A polypeptide is simply a long chain amino acids connected by peptide bonds. When, then, do we have a protein? Are peptides proteins? Are polypeptides proteins? For the most part, a protein is a polypeptide that has folded into a particular structure that has some role or function -- be it a structural role or a catalytic/enzymatic role. So, I often say that a protein is a folded and functional polypeptide. So, all proteins are polypeptides. However, not all polypeptides are proteins; they need to fold into a functional form to be considered a protein. More on protein structure in the Protein Structure Series (links below): Protein Structure (Part 1 of 4) - Levels of Protein Structure: https://www.youtube.com/watch?v=NfMZLk-8r34&index=1&list=PLmGAunhTA6-8ui-A3_XtnTKo_lJY0jYOp Protein Structure (Part 2 of 4) - Secondary Structure - Alpha Helices: https://www.youtube.com/watch?v=V3DgrOG1exY&index=2&list=PLmGAunhTA6-8ui-A3_XtnTKo_lJY0jYOp Protein Structure (Part 3 of 4) - Secondary Structure - Beta Pleated Sheets: https://www.youtube.com/watch?v=koyE9Nplacc&index=3&list=PLmGAunhTA6-8ui-A3_XtnTKo_lJY0jYOp Protein Structure (Part 4 of 4) - Tertiary Structure (Fibrous and Globular Proteins): https://www.youtube.com/watch?v=QSyCPD2qlPs&index=4&list=PLmGAunhTA6-8ui-A3_XtnTKo_lJY0jYOp Myoglobin and Hemoglobin (Compare and Contrast): https://www.youtube.com/watch?v=zbajaSZDl50&index=5&list=PLmGAunhTA6-8ui-A3_XtnTKo_lJY0jYOp Hemoglobin, Bohr Effect, and Fetal Hemoglobin: https://www.youtube.com/watch?v=kKSuuycu5rM&index=6&list=PLmGAunhTA6-8ui-A3_XtnTKo_lJY0jYOp For a suggested viewing order of the videos, information on tutoring, personalized video solutions, and an opportunity to support Moof University financially, visit MoofUniversity.com, and follow Moof University on the different social media platforms. Don't forget to LIKE, COMMENT, and SUBSCRIBE: http://www.youtube.com/subscription_center?add_user=MoofUniversity SUPPORT MOOF UNIVERSITY: http://www.moofuniversity.com/support-moof/ BUY A T-SHIRT https://shop.spreadshirt.com/moofuniversity/ INFORMATION ABOUT TUTORING AND PERSONALIZED VIDEO SOLUTIONS: http://www.moofuniversity.com/tutoring/ INSTAGRAM: https://instagram.com/moofuniversity/ FACEBOOK: https://www.facebook.com/pages/Moof-University/1554858934727545 TWITTER: https://twitter.com/moofuniversity
Views: 27866 Moof University
3.  Kevin Ahern's Biochemistry - Amino Acids
 
47:09
1. Contact me at [email protected] / Friend me on Facebook (kevin.g.ahern) 2. Download my free biochemistry book at http://www.davincipress.com/freeforall.html 3. Take my free iTunes U course at https://itunes.apple.com/us/course/biochemistry/id556410409 4. Lecturio videos for medical students - https://www.lecturio.com/medical-courses/biochemistry.course 5. Course video channel at http://www.youtube.com/user/oharow/videos?view=1 6. Check out all of my free workshops at http://oregonstate.edu/dept/biochem/ahern/123.html 7. Check out my Metabolic Melodies at http://www.davincipress.com/ 8. My courses can be taken for credit (wherever you live) via OSU's ecampus. For details, see http://ecampus.oregonstate.edu/soc/ecatalog/ecourselist.htm?termcode=all&subject=BB 9. Course materials at http://davincipress.com/bb450.html Highlights 1. Molecules can have more than one buffering region. Alanine has both an amine group and a carboxyl group that can gain/lose protons (hydrogen ions). It will thus have two pKas, one for the carboxyl group and one for the amine group. 2. A buffer is at maximum capacity when the concentration of the undissociated acid (HA) equals that of the salt (A-)- . The Henderson Hasselbalch equation further reveals that when this is true, pH = pKa. 3. Amine systems (also in amino acids) have two forms: NH3+ and NH2. Note that the NH3+ is the acid and NH2 is the salt in my nomenclature. Carboxyl systems have two forms too. COOH has no charge and when it loses its proton, COO- has a negative one charge. 3. The value of the Henderson Hasselbalch equation is that by knowing the pH and the pKa of a molecule, the approximate charge of it in solution can be determined. For this class, we will assume that if the pH is more than one unit below the pKa of a group, that the proton is ON it. If the pH is more than one unit above the pKa of the group, the proton is OFF it. This is only useful for estimating charge. Determination of the pI (pH at which a molecule has a charge of exactly zero) requires calculation (described later in class). Protein Structure I 1. Protein structure dictates protein function. The structure of a protein is a function of the sequence of amino acids comprising it. 2. Amino acids are the monomeric (building block) units of proteins. They are covalently joined together in peptide bonds to make proteins (polypeptides). 3. There are 20 amino acids commonly found in proteins and of these 20, 19 have a chiral center and thus can exist in two stereoisomeric forms. The only one that doesn't have a chiral center is glycine. Almost all biologically made amino acids are in the same stereoisomeric form - the 'L' form. The 'D' form occurs only in very rare peptides. 4. Amino acids are grouped into several structural categories based on the composition of their R groups - we will use the designations of your book, as I described in the outline. You will need to know the names of the 20 amino acids of proteins, which of the groups above each one belongs to and will need to be able to predict ionization at given pH values if you are supplied pKa values. Of these amino acids, the ones we will be concerned with have R groups that can ionize. 5. Molecules that are capable of gaining/losing more than one proton, have pKa's that correspond to each functional group that can lose a proton. For example, a simple amino acid, such as alanine, has an amino group (pKa about 9.5) and a carboxyl group (pKa about 2.5). 6. A titration plot for a simple amino acid (no R groups that can lose protons) has two flattened regions - each one occurring at the respective pKa. 7. The sequence of amino acids in a protein is ultimately responsible for all of the properties a protein has. The sequence of amino acids of a protein is referred to as its primary structure. 8. Bonds holding amino acids together in a protein are called peptide bonds and they occur between the alpha amino group of one amino acid and the alpha carboxyl group of the next one. 9. Peptide bonds form resonance structures such that the bond itself behaves like a double bond. Double bonds cannot rotate (unlike single bonds) and thus they define a plane. Alpha carbons on either side of a peptide bond are generally arranged in a trans configuration, except when proline is involved. 10. The bonds around the alpha carbon (the carbon bonded to both an amino group and a carboxy group) can both rotate, however, because they are single bonds. One can thus describe a polypeptide as a series of planes separated by an alpha carbon, with the planes each being rotated a certain number of degrees relative to the alpha carbon. 11. Ramachandran, recognized that not all rotations of phi and psi would be theoretically feasible because steric hindrance would preclude some rotational positions.
Views: 13546 Kevin Ahern
Biochemistry: Protein sequencing problems (1)
 
57:21
Biochemistry: Protein sequencing problems, i.e., the determination of the primary structure of a peptide. Hydrolysis. Dansyl chloride. Proteolytic enzymes. Trypsin. Chymotrypsin. Circular peptides. Thermolysin. Disulfide bonds. Carboxypeptidase. Cyanogen bromide This is a recording of a tutoring session, posted with the student's permission. These videos are offered on a "pay-what-you-like" basis. You can pay for the use of the videos by making a monthly pledge at my Patreon page: http://www.patreon.com/freelanceteacher Or, if you prefer to make a one-time payment, you can do so by using the PalPal "Donate" button on my website: http://www.freelance-teacher.com/videos.htm For a list of all the available video series, arranged in suggested viewing order, go to my website. For a document containing the video (1) homework problems, click here: http://www.freelance-teacher.com/protein_sequencing_homework1.pdf TABLE OF CONTENTS VIDEO (1) 0:00 The amino acid sequence. Amino acid composition 8:10 Hydrolysis 19:10 Dansyl chloride 39:50 Trypsin VIDEO (2) Homework Homework continued. Chymotrypsin Another problem Circular peptides Thermolysin. Disulfide bonds VIDEO (3) Homework Carboxypeptidase Cyanogen bromide tags: education college student students university exam test educational study campus school class
Views: 9617 freelanceteach
Proteins Structures - Primary, Secondary, Tertiary and Quaternary
 
06:50
Proteins are made of many amino acids joined together to form a more complex molecule. This molecule folds further in layers of structure which give the protein its function.
Views: 1265 Tahmid Choudhury
#03 Biochemistry Amino Acids Lecture for Kevin Ahern's BB 450/550
 
47:37
1. Contact me at [email protected] / Friend me on Facebook (kevin.g.ahern) 2. Download my free biochemistry book at http://www.davincipress.com/freeforall.html 3. Take my free iTunes U course at https://itunes.apple.com/us/course/biochemistry/id556410409 4. Lecturio videos for medical students - https://www.lecturio.com/medical-courses/biochemistry.course 5. Course video channel at http://www.youtube.com/user/oharow/videos?view=1 6. Check out all of my free workshops at http://oregonstate.edu/dept/biochem/ahern/123.html 7. Check out my Metabolic Melodies at http://www.davincipress.com/ 8. My courses can be taken for credit (wherever you live) via OSU's ecampus. For details, see http://ecampus.oregonstate.edu/soc/ecatalog/ecourselist.htm?termcode=all&subject=BB 9. Course materials at http://davincipress.com/bb450.html Lecture Highlights 1. Molecules can have more than one buffering region. Alanine, for example has both an amine group and a carboxyl group that can gain/lose protons (hydrogen ions). It will thus have two pKas, one for the carboxyl group and one for the amine group. 2. A buffer system will be at maximum capacity when the concentration of the undissociated acid (HA) equals that of the salt (A-)- (Acid = Salt). The Henderson Hasselbalch equation further reveals that when this is true, pH = pKa. 3. Amine systems (also in amino acids) have two forms NH3+ and NH2. Note that the NH3+ is the acid and NH2 is the salt in my nomenclature. Carboxyl systems have two forms too. COOH has no charge and when it loses its proton, COO- has a negative one charge. 4. Students make mistakes calling things acids and bases. Carboxyl groups are acidic and most think of amine groups as basic. Consequently, they get confused when they think of an amine like NH3+ donating protons (acting like an acid). The same students usually aren't confused, however, about COO- accepting protons (acting like a base). That is why I avoid calling amine groups "bases". 5. The Henderson Hasselbalch equation tells us we can predict the ratio of salt to acid as a function of pH if we know the pKa. Consequently, we can predict the charge on amino acids in a protein as the pH changes. Subtle changes in pH in the body can have drastic changes in protein structure and function. 6. The value of the Henderson Hasselbalch equation is that by knowing the pH and the pKa of a molecule, the approximate charge of it in solution can be determined. Highlights Protein Structure I 1. Protein structure dictates protein function. The structure of a protein is a function of the sequence of amino acids comprising it. 2. Amino acids are the monomeric (building block) units of proteins. They are covalently joined together in peptide bonds to make proteins (polypeptides). 3. There are 20 amino acids commonly found in proteins and of these 20, 19 have a chiral center and thus can exist in two stereoisomeric forms. The only one that doesn't have a chiral center is glycine. Almost all biologically made amino acids are in the same stereoisomeric form - the 'L' form. The 'D' form occurs only in very rare peptides, such as in the cell wall of bacteria (discussed later in the course). 4. Amino acids are grouped into several structural categories based on the composition of their R groups - we will use the designations of your book, as I described in the outline. You will need to know the names of the 20 amino acids of proteins, which of the groups above each one belongs to and will need to be able to predict ionization at given pH values if you are supplied pKa values. The problem solving videos I've posted illustrate this. Of these amino acids, the ones we will be concerned with have R groups that can ionize. These include the aminos, the carboxyls, the sulfhydryl (cysteine) and the hydroxyl or tyrosine. 5. Glycine is the simplest amino acid because it only has a hydrogen as its R-group. It is the only amino acid that doesn't have D and L forms. Another important one structurally is proline. 6. Molecules, such as amino acids, that are capable of gaining/losing more than one proton, have pKa's that correspond to each functional group that can lose a proton. 7. A titration plot for a simple amino acid (no R groups that can lose protons) has two flattened regions - each one occurring at the respective pKa. 8. A zwitterion is a molecule whose net charge is zero. 9. The pI of a molecule is the point at which its charge is exactly zero. 10. The sequence of amino acids in a protein is ultimately responsible for all of the properties a protein has. The sequence of amino acids of a protein is referred to as its primary structure. 11. Bonds holding amino acids together in a protein are called peptide bonds.
Views: 69039 Kevin Ahern
Amino Acids and Peptide Bonds - Condensation Reactions
 
02:22
Check out the following links below! Over 1000+ Medical Questions: http://www.5minuteschool.com DONATE + SUPPORT US: http://paypal.me/5minuteschool Patreon: https://goo.gl/w841fz Follow us on Twitter: http://twitter.com/5MinuteSchool Follow us on Instagram: http://instagram.com/5minuteschool My personal Instagram: http://instagram.com/shahzaebb Contact us: [email protected] ______ Donate: http://www.5minuteSchool.com/Donate Patreon: https://goo.gl/w841fz Website: http://www.5minuteSchool.com Tutoring: http://www.5minuteschool.com/tutoring Essay Writing Service: http://www.5minuteschool.com/essay-writing/ Instagram: www.instagram.com/5minuteschool Twitter: www.twitter.com/5MinuteSchool Background music: Tonez&Re-C - Kyoto https://soundcloud.com/tonez-pro/tonez-re-c-kyoto
Views: 1536 5MinuteSchool
Biochemistry: Protein structure (1)
 
46:43
Biochemistry: Protein structure. Drawing protein chains. Peptide bonds. How to determine the net charge of a peptide chain at different pH’s. Primary structure. Weak interactions; electrostatic interactions, hydrogen bonds, Van der Waals interactions. Hydrophobic effect. Disulfide bonds. Secondary structure; the alpha helix, beta-pleated sheets. Alpha-keratin. Collagen. Tertiary structure. Quaternary structure This is a recording of a tutoring session, posted with the student's permission. These videos are offered on a "pay-what-you-like" basis. You can pay for the use of the videos by making a monthly pledge at my Patreon page: http://www.patreon.com/freelanceteacher Or, if you prefer to make a one-time payment, you can do so by using the PalPal "Donate" button on my website: http://www.freelance-teacher.com/videos.htm For a list of all the available video series, arranged in suggested viewing order, go to my website. For the “Acids and bases” handout discussed in these videos, click here: http://www.freelance-teacher.com/acid_base_reactions.pdf For the “Amino acids” handout discussed in these videos, click here: http://www.freelance-teacher.com/amino_acids.pdf For a document containing the video (1) homework problems, click here: http://freelance-teacher.com/protein_structure_homework1.pdf TABLE OF CONTENTS VIDEO (1) 0:00 Drawing protein chains. Peptide bonds 23:40 How to determine the net charge of a peptide chain at different pH’s 40:10 Characteristics of peptide bonds VIDEO (2) Homework φ and ψ Primary structure Secondary structure. The alpha helix Weak interactions. Electrostatic interactions Hydrogen bonds VIDEO (3) Homework Functions of proteins Van der Waals interactions Hydrophobic effect The alpha helix, continued Alpha-keratin Collagen VIDEO (4) Homework Disulfide bonds Disulfide bonds in alpha-keratin Homework, continued. More about collagen Beta-pleated sheets VIDEO (5) Homework Tertiary structure Quaternary structure VIDEO (6) Homework tags: education college student students university exam test educational study campus school class
Views: 5137 freelanceteach
Amino Acids and Protein Structure.mp4
 
08:47
Welcome to the Humbio Core Chem bootcamp online! The following concepts will be covered in this tutorial: o Structure and properties of amino acids: backbone, side chain, hydrophobic and hydrophilic properties o Formation of a polypeptide: primary, secondary, tertiary, and quaternary structure At 1:51, answer the following question: 1) There are 20 different amino acids. Which roup is used as a unique identifier on each for each amino acid? a) R group (side chain) b) Amino group c) Carboxyl group d) Carbonyl group At 6:41, answer the following question: 2) Of the three "parts/groups" of an amino acid, which will NOT be involved in the hydrogen bonding that holds together a beta sheet? a) R group (side chain) b) Amino group c) Carboxyl group d) Carbonyl group For more practice, see worksheet: https://sites.google.com/site/humbiocore/test/amino-acid-and-protein-structure
Views: 20494 Humbio Core
Proteins: Amino Acids, Polypeptides & 3D Structure | A-level Biology | OCR, AQA, Edexcel
 
03:12
https://goo.gl/31T06Y to unlock the full series of AS, A2 & A-level Biology videos created by A* students for the new OCR, AQA and Edexcel specification. This video will look at the structure of amino acids, peptide bonding through condensation reactions and the different levels of protein structure, including the roles of hydrogen bonding in holding together alpha helices and beta pleated sheets, hydrophobic and hydrophilic interactions, ionic bonding and covalent bonding to produce disulphide bridges. We’ll top everything off with an exam style question.
Views: 10116 SnapRevise
Protein Structure III - Kevin Ahern's BB 450 Lecture #5 2016
 
50:06
Contact me at [email protected] Facebook friend me at https://www.facebook.com/kevin.g.ahern Highlights Protein Structure 3 1. Tertiary structure arises from interactions between amino acids distant in primary sequence. 2. Forces stabilizing tertiary structure include disulfide bonds, hydrogen bonds, ionic interactions, metallic bonds, and hydrophobic interactions. Disulfide bonds are the strongest forces holding tertiary structure together. 3. Most proteins that are in cells are globular - have tertiary structure.. 4. Folded proteins found in aqueous environments have a bias such hydrophilic amino acids tend to be on the outside of the protein and hydrophobic amino acids tend to be on the inside. 5. A protein with tertiary structure typically contains mulitiple secondary structures. 6. Random coils are distinguished from reverse turns by being longer, typically and no set orientation. 7. Unfolding of a protein requires breaking the forces within it that stabilize tertiary structure. 8. Tertiary structure is stabilized by disulfide bonds, ionic interactions, hydrogen bonds, hydrophilic. 9. Breaking of bonds stabilizing tertiary structure can occur by mercaptoethanol (breaks disulfide bonds), dithiothreitol (breaks disulfide bonds), detergent (breaks hydrophobic interactions), heat (breaks hydrogen bonds), urea (breaks hydrogen bonds), pH (breaks ionic bonds), or chelators (breaks metallic bonds). 10. Disulfide bonds are important structural components of proteins. They form when the sulfhydryls of two cysteines are brought together in close proximity. Some chemicals, such as mercaptoethanol, can reduce the disulfides (between cysteine residues) in proteins to sulfhydryls. In the process of transferring electrons to the cysteines, the sulfhydryls of mercaptoethanol become converted to disulfides. 11. The enzyme ribonuclease (RNase) is interesting in being very stable to heat and other things that denature/inactivate other proteins. (By the way, denaturation is a word that means the tertiary and/or quaternary structure of a protein is disrupted.). RNase has disulfide bonds that help it to remain resistant to denaturation. Heating it to 100 Celsius, which denatures most proteins does not denature RNase. Breaking the disulfide bonds of RNAse with a reagent like mercaptoethanol followed by heating to 100 Celsius to destroy hydrogen bonds (or treatment with urea) causes loss of activity. If one allows the hydrogen bonds to reform slowly, some of the enzyme's activity reappears, which indicates that the information necessary for proper folding is contained in the primary structure (amino acid sequence). 12. Interestingly, removal of the mercaptoethanol and urea from the solution allows RNase to refold, reestablish the correct disulfide bonds, and regain activity. Clearly, the primary sequence of this protein is sufficient for it to be able to refold itself to the proper configuration. 13. Structural domains are common structural features found in many proteins. Examples from class include leucine zippers (interacting leucine side chains) found in DNA binding proteins, helix-turn-helix motifs (DNA binding proteins), zinc fingers (DNA binding proteins), SH2 domains (protein-protein binding - often in signaling proteins), and pleckstrin homology domains (also in signaling proteins). 14. Folding is necessary for proteins to assume their proper shape and function. The instructions for folding are all contained in the sequence of amino acids, as demonstrated by refolding of RNAse after denaturation, but we do not yet understand how those instructions are carried out rapidly and efficiently. 15. Proper folding of a protein is essential. Cells have complexes called Chaperonins that help some proteins to fold properly. Misfolding of proteins is implicated in diseases such as mad cow disease and Creutzfeld-Jacob disease in humans. The causative agent in these diseases is a "contagious" protein called a prion that is coded by the genome of each organism. When it doesn't fold properly, it helps induce other copies of the same protein to misfold as well, resulting in plaque-like structures that destroy nerve cells. 16. Amyloids are a collection of improperly folded protein aggregates in humans that arise at least partly from problems with folding. Diseases and relevant proteins include Alzheimer's disease (amyloid beta), Parkinson's disease (alpha-synuclein), Huntington's disease (huntingtin), rheumatoid arthritis (serum Amyloid A), and fatal familial insomnia (PrPSc) 17. The Gro-EL / Gro-ES complex forms a chaperonin complex in E. coli. Chaperonins, for example, allow proteins to have a chamber in which hydrophobic amino acids are precluded from interactions with other proteins and then they fold naturally. 18. Cells have a structure called a proteasome that breaks down proteins when necessary (often after damage).
Views: 2552 Kevin Ahern
#05 Biochemistry Protein Tertiary/Quaternary Structure Lecture for Kevin Ahern's BB 450/550
 
49:53
1. Contact me at [email protected] / Friend me on Facebook (kevin.g.ahern) 2. Download my free biochemistry book at http://www.davincipress.com/freeforall.html 3. Take my free iTunes U course at https://itunes.apple.com/us/course/biochemistry/id556410409 4. Lecturio videos for medical students - https://www.lecturio.com/medical-courses/biochemistry.course 5. Course video channel at http://www.youtube.com/user/oharow/videos?view=1 6. Check out all of my free workshops at http://oregonstate.edu/dept/biochem/ahern/123.html 7. Check out my Metabolic Melodies at http://www.davincipress.com/ 8. My courses can be taken for credit (wherever you live) via OSU's ecampus. For details, see http://ecampus.oregonstate.edu/soc/ecatalog/ecourselist.htm?termcode=all&subject=BB 9. Course materials at http://davincipress.com/bb450.html Lecture Highlights Highlights Protein Structure 3 1. Another type of fibrous protein is collagen, the most abundant protein in your body. It contains three intertwined helices comprised of abundant repeating units of glycine, proline, and hydroxylproline 2. Hydroxylation of proline is a post-translational modification (occurs after the protein is made) and the hydroxyls are placed there in a reaction that uses vitamin C. 3. The hydroxyls of hydroxyproline can react with other, forming covalent cross-links that make the collagen fibers more sturdy. 4. Tertiary structure relates to interactions between amino acids in a protein that are not close in primary sequence. These interactions are made possible by folding to the protein chain to bring the distant amino acids closer together. 5. Tertiary structure is stabilized by disulfide bonds, ionic interactions, hydrogen bonds, hydrophilic, and hydrophobic interactions. Disulfide bonds are the strongest forces holding tertiary structure together, as they are covalent bonds. 6. Most proteins that are in cells are globular in nature. 7. Myoglobin is protein that acts as an oxygen 'battery', storing oxygen in muscles for when it is needed. Myoglobin contains a heme group that contains iron. Heme is a 'prosthetic group', which refers to a non-amino acid containing group that binds to a protein and augments its function. 8. Amino acid residues in myoglobin are arranged such that hydrophilic (and what your book calls ionic) amino acids are arranged on the outside and hydrophobic amino acids are largely arranged on the inside. 9. Porin is a membrane protein. Proteins embedded in membranes often have external amino acids that are hydrophobic so they can interact with the non-polar portions of membranes. Porin, in addition, has a hole in the center that allows water to pass through it. The amino acids in porin are arranged with non-polars outside and polars inside. 10. Quaternary structure of proteins relates to the interactions between separate polypeptide chains within the protein. The word polypeptide refers to a polymer of amino acids. A protein may contain one or more polypeptides and is folded and may be covalently modified. 11. Hemoglobin (and many other proteins) have multiple polypeptide subunits. Interactions between the subunits include disulfide bonds, ionic interactions, hydrogen bonds, hydrophilic, and hydrophobic interactions. Modification of the quaternary structure of a protein may have the same effects as modification of its tertiary structure - alteration of its function/activity. 12. Folding is necessary for proteins to assume their proper shape and function. The instructions for folding are all contained in the sequence of amino acids, but we do not yet understand how those instructions are carried out rapidly and efficiently. Levinthal's paradox illustrates the fact that folding is not a random event, but rather based on an ordered sequence of events arising from the chemistry of each group. 13. Proper folding of a protein is essential. Cells have complexes called Chaperonins that help some proteins to fold properly. Misfolding of proteins is implicated in diseases such as mad cow disease and Creutzfeld-Jacob disease in humans. The causative agent in these diseases is a "contagious" protein that is coded by the genome of each organism. When it doesn't fold properly, it helps induce other copies of the same protein to misfold as well, resulting in plaque-like structures that destroy nerve cells.
Views: 28550 Kevin Ahern
What is a Protein? Learn about the 3D shape and function of macromolecules
 
03:39
A new version of this video is available at https://www.youtube.com/watch?v=wvTv8TqWC48 Proteins play countless roles throughout the biological world, from catalyzing chemical reactions to building the structures of all living things. Despite this wide range of functions all proteins are made out of the same twenty amino acids, but combined in different ways. The way these twenty amino acids are arranged dictates the folding of the protein into its unique final shape. Since protein function is based on the ability to recognize and bind to specific molecules, having the correct shape is critical for proteins to do their jobs correctly. A PDF flyer accompanies this video at PDB-101 at http://bit.ly/RK7OmG Animation by Maria Voigt, narration by Monica Sekharan
Views: 551141 RCSBProteinDataBank
MCAT®: Amino Acids Part I - Peptide bond formation
 
03:19
► MCAT| Biological and Biochemical Foundations of Biological Systems |Content Category 1A: Structure and function of proteins and their constituent amino acids| Amino Acids - Part I ► Lecture Description: - Topics include: Absolute configuration of amino acids at the α-position, dipolarity in amino acids, classification of amino acids, important reactions of amino acids including: sulfur linkage, peptide linkage and hydrolysis. ► Watch more at Masterthecontent.com|Your career. Our passion. - View complete lessons complete with multiple in-lecture examples - Interactive table of contents makes it easy to search for and jump to specific topics - Interact with instructors ► Connect with us: - https://www.facebook.com/MasterTheContent - https://twitter.com/MTCtoday - https://plus.google.com/u/0/100536207031817220229/about
Views: 214 Master the Content
#5 BB 350 Protein 3D Structure I - Kevin Ahern's Biochemistry Online
 
54:03
1. Contact me at [email protected] / Friend me on Facebook (kevin.g.ahern) 2. Download my free biochemistry book at http://biochem.science.oregonstate.edu/biochemistry-free-and-easy 3. Take my free iTunes U course at https://itunes.apple.com/us/course/biochemistry/id556410409 4. Check out my free book for pre-meds at http://biochem.science.oregonstate.edu/biochemistry-free-and-easy 5. Course video channel at http://www.youtube.com/user/oharow/videos?view=1 6. Check out all of my free workshops at http://www.youtube.com/playlist?list=PLlnFrNM93wqyTiCLZKehU1Tp8rNmnOWYB&feature=view_all 7. Check out my Metabolic Melodies at http://www.davincipress.com/metabmelodies.html 8. Take my courses for credit (wherever you live) via OSU's ecampus. For details, see http://ecampus.oregonstate.edu/soc/ecatalog/ecourselist.htm?termcode=all&subject=BB 9. Course materials at http://oregonstate.edu/instruct/bb350 Lecture Highlights Protein Structure 1. Peptide bonds are the covalent bonds that join together individual amino acids within a protein. They are formed in a reaction in the ribosome in which the carboxyl group of one amino acid is joined to the amino end of another amino acid. Proteins always have a free alpha amino end and a free alpha carboxyl end. 2. Interesting molecules made from or containing amino acids include histamine (involved in allergies), nutrasweet (artificial sweetener made of aspartic acid and phenylalanine), and glutathione (cellular antioxidant). 3. Calculating the charge on a polypeptide is simple. One simply tallies the charge of the alpha carboxyl group, the alpha amino group, and all of the R groups. Note that the internal carboxyl/amino groups are destroyed in making the peptide bond. 4. Peptide bonds act like double bonds due to electronic resonance. 5. Primary structure of a polypeptide corresponds to the sequence of amino acids comprising it. Every property of a protein ultimately traces to the primary structure of a protein. As the primary structure changes, so too does the nature of what the protein can do changes. 6. Secondary structure arises from interactions between amino acids close to each other (within 10) in primary sequence. Alpha helices are common secondary structures in polypeptides. Alpha helices are stabilized by hydrogen bonds between the oxygen of a carbonyl group and a hydrogen on the amide four amino acids away. Forces that destabilize hydrogen bonds also destabilize alpha helices. Heat is one such force that destabilizes alpha helices. Soap is another. 7. Beta strands are other protein secondary structures. When aligned in multiple units, beta strands are referred to as beta sheets. The forces holding the strand together are hydrogen bonds. 8. Both alpha helices and beta sheets were discovered by the most famous scientist ever to graduate from OSU, Dr. Linus Pauling. 9. Fibrous proteins, such as the keratin of your hair, contain almost exclusively primary and secondary structure, but no tertiary or quaternary structure. Examples include keratin (hair, nails) and collagen. Proteins that 'fold' into glob-like structures are known as globular proteins. Globular proteins are far more common than fibrous proteins. 10. Globular proteins have a folded structure arising from turns between regions of secondary structure. Tertiary structure arises from interactions between amino acids that are NOT close in primary structure. 11. Turns are critically important for determining the overall three-dimensional structure of a protein. Turns occur over about a distance of 4 amino acids and involve amino acids with bulky or inflexible side chains. A common component of turns is the amino acid proline. 12. The following forces stabilize protein structure • Primary = peptide bonds (covalent) • Secondary = hydrogen bonds • Tertiary = hydrogen bonds, ionic interactions, hydrophobic interactions, covalent (disulfide) bonds, ionic interactions 13. Proteins can have many regions of alpha helix and beta sheets within them. The overall 3D structure of a protein is a function of how all of them are arranged together. 14. Globular proteins have many folds and turns than arrange the helices and sheets into unusual patterns. The process whereby the protein assumes is final shape is called 'folding.' 15. Globular proteins that are soluble in water usually have their polar amino acids on the outside in contact with water and their non-polar amino acids on the inside associating with each other (thus avoiding water). 16. Disruption of forces that stabilize protein structure cause folded proteins to unfold. Unfolded proteins are not functional. We describe them as denatured. Denaturing agents include heat, detergent, acid or base.
Views: 8105 Kevin Ahern
Macromolecules Part Two: Proteins
 
13:27
Macromolecules Part Two: Proteins. Amino acids, peptide bonds, protein structure (primary, secondary, tertiary, quaternary). PowerPoints slides from video found here: http://tdelia-irsc.weebly.com/course-lecture-material.html
Views: 2648 tdelia_biology