Final answer:
N-acetylglucosamine (NAG) is structurally similar to glucose, making it one of the sugar molecules found in bacterial cell walls composed of peptidoglycan.
Step-by-step explanation:
Structurally similar to glucose, N-acetylglucosamine (NAG) is one of the two types of sugar molecules found in the peptidoglycan complex polysaccharide that makes up bacterial cell walls. Peptidoglycan is composed of regularly alternating NAG and N-acetylmuramic acid (NAM) sugar molecules. While NAG is similar to glucose, the other options, Ribose, Sucrose, and Fructose, have different structures and cannot be considered structurally similar to glucose. Therefore, the correct answer is (A) N-acetylglucosamine (NAG).