Glycogen synthesis uses simple sugars as building blocks

Steps:

• Identify glycogen as a branched polysaccharide that stores glucose in animals.
• Recall glycogenesis: the process linking glucose units to form glycogen chains.
• Note the monomer: glucose, a simple sugar (monosaccharide).
• Confirm via biochemistry: UDP-glucose adds glucose residues to growing glycogen.

Why C is correct:

• Glycogen forms by polymerization of glucose (C6H12O6), a simple sugar, through α-1,4 and α-1,6 glycosidic bonds.

Why the others are wrong:

• A. Amino acids polymerize into proteins, not carbohydrates like glycogen.
• B. Fatty acids build lipids such as triglycerides, unrelated to glycogen synthesis.
• D. Starch is a plant polysaccharide similar to glycogen but serves as a source of glucose, not the direct building block.

Final answer: C