6. Which of the following amino acid do not fall under the category of an essential amino acid?
A. Histidine
B. Leucine
C. Glycine
D. Methionine
8. The inputs to one cycle of the urea cycle are
A. 1 molecule of aspartic acid, 1 molecule of ammonia, 1 molecule of carbon dioxide, 3 molecules of ATP
B. 1 molecule of urea, 1 molecule of ammonia, 3 molecules of ATP and 1 molecule of fumaric acid
C. 1 molecule of fumaric acid, 1 molecule of urea, 3 molecules of AMP
D. None of the above