Question

macromolecules
the picture above shows two monomer units of a nucleic acid chain. what are the components that make up each nucleotide monomer?
a. glucose, a phosphate group, and an amino acid
b. glucose, a phosphate group, and a nitrogenous base
c. a five - carbon sugar, a phosphate group, and a nitrogenous base
d. a five - carbon sugar, a phosphate group, and an amino acid

Explanation:

To determine the components of a nucleotide monomer (from nucleic acid), recall: Nucleotides (monomers of DNA/RNA) consist of a five - carbon sugar (ribose or deoxyribose), a phosphate group, and a nitrogenous base (adenine, thymine/uracil, cytosine, guanine).

• Option A: Glucose is a six - carbon sugar (not in nucleotides), and amino acids are for proteins, so A is wrong.
• Option B: Glucose is not a component of nucleotides, so B is wrong.
• Option C: Matches the correct components (five - carbon sugar, phosphate, nitrogenous base).
• Option D: Amino acids are for proteins, not nucleotides, so D is wrong.

Answer:

C. a five - carbon sugar, a phosphate group, and a nitrogenous base