Collegeboardcom ap biology 2008 scoring guidelines

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: apcentral.collegeboard.com. AP® BIOLOGY 2008 SCORING GUIDELINES Question 1 1. The physical structure of a protein often reflects and affects its function. (a) Describe THREE types of chemical bonds/interactions found in proteins. For each type, describe its role in determining protein structure. (6 points; 1 point for bond/interaction description, 1 point for description of role) Bond/interaction Covalent/ peptide Disulfide/ covalent Hydrogen van der Waals Hydrophobic Ionic Description sharing electrons OR linking amino acids together disulfide, S–S bond (bridges); sulfur-containing R group bonding H–O or H–N interactions unequal electron clouds in R group; dipole moments nonpolar R groups charged R groups Role associated to bond/interaction amino acid sequence OR primary structure (no credit for chain or polypeptide alone) tertiary or quaternary structure α helix, β sheet; secondary, tertiary, or quaternary structure tertiary or quaternary structure tertiary or quaternary structure tertiary or quaternary structure (b) Discuss how the structure of a protein affects the function of TWO of the following. (3 points maximum) Muscle contraction (1 point for each bullet; 2 points maximum) • Actin (thin filaments) and myosin; cross-bridges OR filamentous proteins slide past each other. • Troponin/tropomyosin interaction blocks binding of myosin to actin. • Ca2+ changes troponin shape/binding of troponin-tropomyosin to actin altered. • ATP/ADP changes myosin structure. Regulation of enzyme activity (2 points maximum) • Shape change caused by (1 point for each bullet) o Binding of a...
View Full Document

This note was uploaded on 11/23/2009 for the course BIOLOGY 1101 taught by Professor Keith during the Winter '05 term at The University of Oklahoma.

Ask a homework question - tutors are online