Question

multiple choice question
____ are the building blocks of proteins and they exist in ____ different naturally occurring forms.
o amino acids; 20
o polysaccharides; 20
o nucleotides; 4
o fatty acids; 20

Explanation:

Amino acids are the building - blocks of proteins, and there are 20 naturally - occurring amino acids. Polysaccharides are complex carbohydrates, nucleotides are building blocks of nucleic acids, and fatty acids are components of lipids.

Answer:

A. Amino acids; 20