Final answer:
Amino acids are to proteins what glucose molecules are to starch, as both serve as building blocks for larger polymers.
Step-by-step explanation:
Just as amino acids are the monomers that come together to form proteins, glucose molecules are the monomers that link together to form starch. Starch is composed of many glucose units bonded together to form a polymer.
Proteins are indeed polypeptides made from long chains of amino acids linked by peptide bonds. Similarly, carbohydrates like starch are polymers composed of simpler sugar units such as glucose. Hence the correct answer to the analogy 'Amino acid is to a protein as a glucose molecule is to...' would be 'A. Starch'.