Question

question 3 (1 point)
the functional group which makes each of the twenty amino acid unique is:
o a phosphate group
b r group
o c carboxyl group
d amino group
o e pentose sugar

Explanation:

All amino acids have a central carbon atom bonded to an amino group ($-NH_2$), a carboxyl group ($-COOH$), a hydrogen atom, and an $R$ group. The $R$ group varies among different amino acids, giving each amino acid its unique properties. Phosphate groups are not part of the basic amino acid structure. Pentose sugar is not a functional group in amino acids. The amino and carboxyl groups are common to all amino acids and do not account for their uniqueness.

Answer:

B. R group