Question

protein molecules are composed of long chains of ______.
a. dna
b. amino acids
c. ribosomes
d. rna

Explanation:

To solve this, we analyze each option:

• Option A: DNA is a nucleic acid, not the building block of proteins.
• Option B: Proteins are polymers made by linking amino acids through peptide bonds, so long chains of amino acids form protein molecules.
• Option C: Ribosomes are organelles involved in protein synthesis, not the components of proteins.
• Option D: RNA is a nucleic acid, not the building block of proteins.

Answer:

B. amino acids