1. Which of the following amino acids has a side chain that can form a disulfide bond, contributing to the tertiary structure of a protein? A. Glycine B. Proline C. Cysteine D. Alanine Correct Answer: C. Cysteine Rationale: Cysteine contains a thiol group which can oxidize to form a disulfide bond, stabilizing the protein's structure. 2. In the context of carbohydrate metabolism, what is the primary purpose of the pentose phosphate pathway? A. To generate ATP B. To produce ribose-5-phosphate for nucleotide synthesis C. To degrade glucose D. To synthesize fatty acids Correct Answer: B. To produce ribose-5-phosphate for nucleotide