1. When the amino acid alanine (R-group is CH3) is added to a solution with a pH of 7.3, alanine becomes
A. a cation
B. nonpolar
C. a zwitterions
D. an isotope
2. What is the end product of leucine metabolism?
A. Acetyl-CoA
B. Pyruvic acid
C. Oxaloacetic acid
D. Acetyl carnitine
3. What is the heaviest of the twenty amino acids?
A. Phenylalanine
B. Tryptophan
C. Tyrosine
D. Histidine
4. Which of the following amino acids can form hydrogen bonds with their side (R) groups?
A. Asparagine
B. Aspartic acid
C. Glutamine
D. All of these
5. The isoelectric point of an amino acid is defined as the pH
A. where the molecule carries no electric charge
B. where the carboxyl group is uncharged
C. where the amino group is uncharged
D. of maximum electrolytic mobility