Question

16 multiple choice 1 point which of the following are not true of proteins? a. proteins are considered the chief \doer\ of the cell. b. proteins serve as key structural components of cells and living organisms. c. proteins serve as enzymes. d. proteins serve as the main energy source for cellular respiration.

Explanation:

• Option A: Proteins perform many cellular functions, so they are the chief "doer" of the cell (true).
• Option B: Proteins like collagen are key structural components (true).
• Option C: Most enzymes are proteins (true).
• Option D: The main energy source for cellular respiration is glucose (carbohydrates), not proteins (proteins are used for energy only when other sources are depleted, not the main source). So this statement is NOT true.

Answer:

D. Proteins serve as the main energy source for cellular respiration.