The body normally makes tyrosine from the essential amino acid:
a. leucine.
b. lysine.
c. isoleucine.
d. valine.
e. phenylalanine.
Question 2
Which of the following accounts for the differences among the various amino acids?
a. the presence or absence of nitrogen
b. the amine group
c. the side chain
d. the type of bonds
e. the acid group