Each amino acid molecule contains a structurally unique part called the _____ group.
A)amino
B)amine
C)carboxylic acid
D)R-

Question

Each amino acid molecule contains a structurally unique part called the _____ group. 
A)amino
B)amine
C)carboxylic acid
D)R-

Quizplus · Accepted Answer

Each amino acid molecule contains a structurally unique side chain or R-group, which can be an alkyl or aromatic group, or contain functional groups such as hydroxyl, sulfhydryl, or carboxyl groups. Therefore, choice D is the correct answer, as it refers to the R-group. Amino, amine, and carboxylic acid groups are all present in amino acids but are not structurally unique to each amino acid.

Each Amino Acid Molecule Contains a Structurally Unique Part Called