Question

an organic molecule made up of linked amino acid subunits is a(n):
nucleic acid.
inorganic molecule.
protein.
carbohydrate.

Explanation:

Proteins are organic molecules composed of linked amino acid subunits (polypeptide chains). Nucleic acids use nucleotides, carbohydrates use monosaccharides, and inorganic molecules lack carbon-hydrogen bonds, so they do not match the description.

Answer:

protein.