Practice!

Sample Problem

Which of the following is true about the boxed off region in the above amino acid? (Check all that apply)

(A) It is an amino group.

(B) It is a carboxyl group.

(C) It is acidic.

(D) It donates an OH during dehydration synthesis.

Solution

(B), (C), and (D) are all correct. The amino group is the NH2 group on the other side of the amino acid. This group is what gives amino acids the “acid” part of their name. During dehydration synthesis, the OH group from the carboxyl of one amino acid and the H atom from the amino group of another amino acid will combine to form water.