Which of the following functional groups is present in amino acids?

A) sulfhydryl
B) amino
C) carboxyl
D) hydroxyl
E) All of the answer choices are present in amino acids.

Amino

Refers to amino acids, the building blocks of proteins, characterized by the presence of both an amino group and a carboxyl group.

Carboxyl

A carboxyl group is a functional group consisting of a carbon atom double-bonded to an oxygen atom and also bonded to a hydroxyl group, symbolized as -COOH.

Sulfhydryl

A functional group consisting of a sulfur atom bonded to a hydrogen atom (-SH), important in the structure and function of proteins.