Biochem Exam 2 Study Guide PDF

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Biochemistry (4610) Highlights of Key Points Keep in mind that you are expected to build on your knowledge and not forget the information after an exam. Chapters 6, 7, 8.1-8.2, 11, 12 (Exam 2) Protein Structure and Folding Know the properties of α-keratin, collagen and silk fibroin α-keratin: has α-helices in clockwise direction wrapping together in a left-handed direction, rich in disulfide bonds and low in Gly and Pro collagen: helix, left-handed- rich in Pro and Hyp also Gly makes up 1/3 – oxidizes Lys silk fibroin: β-sheet layer, Ala Ser and Val – all similar size Understand the trends of 3° Structure of globular proteins, including location of amino acids Globular – 3D super-secondary structures (recognizable pattern of 2 or more secondary structures) and independently folded Determine through x-ray diffraction Understand that proteins are dynamic Can move and bend Understand the forces maintaining 3-D structure of proteins and the contributions of each Hydrophobic interactions, h-bonds, and electrostatic interactions (van der waals/ ion pairs) Know what causes protein denaturation Heat: disrupt noncovalent interactions pH extremes: decrease attractions, increase repulsions Detergents, Organics Chaotropic agents: disrupt structure of water, disrupting hydrophobic interactions Understand the concepts of protein folding and the forces most important in protein folding. Form local secondary structures first, form hydrophobic interior, form tertiary structure (chaperone proteins) Understand the proteins which aid folding, particularly chaperone proteins and the GroEL/GroES system. Disulfide isomerase, prolyl cis-trans isomerase and GroEL/GroES binds and refolds improperly folded proteins – cis and trans rings with hydrophobic interior

Know what is meant by subunits and quaternary structure. Subunit: individual polypeptide chains Oligomer: multi-subunit protein Protomer: identical structural units in oligomers Understand that structure dictates function and consequences of altered structure (ex. prions). Results in diseases, forms aggregates Protein Structure and Function Hemoglobin (Hb) and Myoglobin (Mb) Know the general structure and function of hemoglobin and myoglobin. Hb and Mb are carriers of O2 Mb: one unit for O2 to bind Hb: four units for O2 to bind Understand how O2 binding to Hb relates to significant conformational change of Hb. O2 binding causes conformational change: R (relaxed with high affinity) and T (taut with low affinity) Understand Hill coefficients and how to interpret values. >+1 = positive cooperativity...