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PROTEIN STRUCTURE. Aeron Perlman Marcos San Martin James Loya. Chemistry 131 . Image: explow.com. PROTEIN STRUCTURE. Primary Secondary Tertiary Quaternary. Protein Structure.
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PROTEIN STRUCTURE Aeron Perlman Marcos San Martin James Loya Chemistry 131 Image: explow.com
PROTEIN STRUCTURE Primary Secondary Tertiary Quaternary
Protein Structure • Proteins are polymer chains of amino acids that are chemically bonded, forming a backbone, with “R” groups coming off that determine its properties. • The amino acids are joined by C-N bonds between the amino acids into peptide chains, which are called proteins when they are around 50 amino acids or longer. Source: Nick Bucker. (June 03, 2012). 131Biochem.(PowerPoint presentation). Retrieved from http://angel.northseattle.edu/section/default.asp?id=NSCC%5FS12%5F2220
Biological Functions of Proteins Source: Nick Bucker. (June 03, 2012). 131Biochem.(PowerPoint presentation). Retrieved from http://angel.northseattle.edu/section/default.asp?id=NSCC%5FS12%5F2220
Classification Fibrous or Globular • Fibrous are long rod shaped molecules that bind together to form strong fibers which form connective tissues. Eg: collagen elastin and keratin. Fibrous proteins are water insoluble. • Globular proteins are glob like! They are dissolvable in water or form suspensions. They serve as transport proteins, moving things through the blood. Hemoglobin.
Classification Simple or Conjugated • Simple proteins: contain only amino acid residues • Conjugated proteins: contain amino acid residues and other organic or inorganic components called prosthetic groups, which further classify the protein. Hemoglobin is a metalloprotein because of the iron it carries. Proteins containing lipids and carbohydrates are called lipoproteins and glycoproteins.
Protein Structure • Proteins are large complex molecules which serve specific functions. • Each protein is made up of a specific series of amino acids which then take on a specific shape to perform its task. • Without the proper shape a protein is rendered useless. A protein is in its correct form it is said to be in its natural state, however when it loses that shape it is said to be denatured.
Protein Structure Denaturation • Denaturation is caused by extremes in environment. • Typically temperature and pH values outside normal functional ranges. • These extremes disrupt the stabilizing structures that hold the protein in its unique shape, causing it to distort and rendering it inactive. This is the mechanism used to sterilize items in an autoclave. • High heat combined with pressure denature the proteins of bacteria and viruses that cause disease.
Protein Structure Denaturation Source: Seager S, Slabaugh M. (2011). Chemistry for Today 7th Ed. Belmont CA. Brooks/Cole. Pg. 605
Primary Structure of Proteins • Linear chain of “random” amino acids are linked together in a unique order which causes it to fold and curl into its distinctive shape so it functions properly. • Insulin is an example of a primary protein structure of two amino acid residues linked by disulfide bridges.
Primary Structure of Proteins Insulin Source: Nick Bucker. (June 03, 2012). 131Biochem.(PowerPoint presentation). Retrieved from http://angel.northseattle.edu/section/default.asp?id=NSCC%5FS12%5F2220
Secondary Structure of Proteins Two Types: • Alpha helix-single protein chain • Beta pleated sheet-protein chains
Secondary Structure of Proteins Alpha helix • Alpha helix-single protein chain that spirals and connects to itself with hydrogen bonds, forming a helical structure. Like a single side of a DNA strand. • Common in proteins which form long bundles like keratin in hair.
Secondary Structure of Proteins Alpha Helix Source: Nick Bucker. (June 03, 2012). 131Biochem.(PowerPoint presentation). Retrieved from http://angel.northseattle.edu/section/default.asp?id=NSCC%5FS12%5F2220
Secondary Structure of Proteins β-Pleated Sheet • Beta pleated sheet-protein chains are lined up side by side and connected by hydrogen bonds. The pleated shape comes from the orientation of the amino acids in space. “Bonds are formed between the amide carbonyl oxygen on one chain and the amide hydrogen of an adjacent chain”(598). This form is usually a small part of a larger protein. • Seager S, Slabaugh M. (2011). Chemistry for Today 7th Ed. Belmont CA. Brooks/Cole
Secondary Structure of Proteinsβ-Pleated Sheet Source: Nick Bucker. (June 03, 2012). 131Biochem.(PowerPoint presentation). Retrieved from http://angel.northseattle.edu/section/default.asp?id=NSCC%5FS12%5F2220
Tertiary Structure of Proteins • A three dimensional shape that is caused by the bonding interactions between “R” groups of the amino acid residues in the protein,” Seager S., Slabaugh M. p.599. Seager S, Slabaugh M. (2011). Chemistry for Today 7th Ed. Belmont CA. Brooks/Cole Pg. 599
Tertiary Structure of Proteins Source: Nick Bucker. (June 03, 2012). 131Biochem.(PowerPoint presentation). Retrieved from http://angel.northseattle.edu/section/default.asp?id=NSCC%5FS12%5F2220
Tertiary Structure of ProteinsFour Types of R-group Interactions Source: Seager S, SlabaughM. (2011). Chemistry for Today 7th Ed. Belmont CA. Brooks/Cole.
Tertiary Structure of Proteins Source: Nick Bucker. (June 03, 2012). 131Biochem.(PowerPoint presentation). Retrieved from http://angel.northseattle.edu/section/default.asp?id=NSCC%5FS12%5F2220
Hydrophobic Interactions Source: Seager S, Slabaugh M. (2011). Chemistry for Today 7th Ed. Belmont CA. Brooks/Cole
Quaternary Structure of Proteins • A protein that is comprised of two or more subunits (primary, secondary or tertiary proteins) held together by ionic attractions, disulfide bridges, hydrogen bonds and hydrophobic forces. Seager S, Slabaugh M. (2011). Chemistry for Today 7th Ed. Belmont CA. Brooks/Cole
Quaternary Structure of Proteins • Hemoglobin is such a structure with two alpha chains and two beta chains each containing a heme group which is connected to an iron atom. Source: Seager S, Slabaugh M. (2011). Chemistry for Today 7th Ed. Belmont CA. Brooks/Cole Nick Bucker. (June 03, 2012). 131Biochem.(PowerPoint presentation). Retrieved from http://angel.northseattle.edu/section/default.asp?id=NSCC%5FS12%5F2220
Thanks!!! Sources: • Nick Bucker. (June 03, 2012). 131Biochem.(PowerPoint presentation). Retrieved from http://angel.northseattle.edu/section/default.asp?id=NSCC%5FS12%5F2220 • Seager S, Slabaugh M. (2011). Chemistry for Today : General, Organic, & Biochemistry -7th Ed. (Print). Belmont CA. Brooks/Cole