BIOCHEMISTRY FINAL EXAM 2026/2027 UPDATE GRADED A+ (111pages)

1. The β -pleated sheet forms when two or more peptide chain, called strands, line up side by side with the C=O and N-H bonds in the plane of the sheets A. true a. false 2. when the amino acid alanine (the R group is ـCH3) is added to a solution with a pH of 7.3 alanine become A. zwitterion B. nonpolar C. cation D. anion 3. the α amino acid have a carboxyl group with a pK around and an amino group with a pK near : A. 1.1, and 12.1 B. 6.5, and 8.0 C. 3.3, and 10.5 D. 2.2, and 9.4 4. an amino acid can act as an acid and a base A. true B. false 5. In an aqueous solution, protein conformation is determined by two major factors. One is the formation of the maximum number of hydrogen bonds. The other is the A. formation of the maximum number of hydrophilic interactions B. Placement of hydrophobic amino acid residues within the interior of the protein C. Minimization of entropy by the formation of a water solvent shell around the protein D. Maximization of ionic interactions 6. Calculate the isoelectric point of aspartic acid pK1 -COOH = 2.01 pK2 -NH3+ = 9.8 pK3 -R group = 3.83 A. 5.9 B. 2.92 C. 8.62 D. 6.82 7. What is a peptide bond A. Bond that holds two amino acids together B. Bond that holds the phosphate group of one nucleotide and a sugar of a neighboring nucleotide C. A bond that is formed by the sharing of electrons D. A bond that holds hydrogen and oxygen molecules together