Chapter 4 - Key Concepts & Review Points

Question 1

At neutral pH, the amino group of an amino acid is ____________ and its carboxylic acid group is ____________.

Answer 1

protonated

deprotonated (ionized)

Question 2

Proteins are polymers of amino acids joined by ____________.

Answer 2

peptide bonds

Question 3

The 20 standard amino acids can be calculated as ____________, ____________, or _____________.

Answer 3

nonpolar
uncharged polar
charged

Question 4

The ________ values of the ionizable groups of amino acids may be altered when the amino acid is part of a polypeptide.

Answer 4

pK

Question 5

Amino acids are chiral molecules. Only ____-amino acids are found in proteins (some bacterial peptide contain ____-amino acids).

Answer 5

L

D

Question 6

Amino acids may be covalently modified ____________ they have been incorporated into a polypeptide.

Answer 6

after

Question 7

Individual amino acids and their derivatives have diverse ____________.

Answer 7

physiological functions