15: Amino Acid/Nucleotide Metabolism

Question 1

The class of enzyme that catalyzes the cleavage of the peptide bond in proteins is \_\_\_\_\_\_\_\_\_\_
  A. protease 
  B. kinase 
  C. transferase 
  D. dehydrogenases

Answer 1

A. protease

Question 2

In the breakdown of amino acids in birds, the excess N is excreted as \_\_\_\_\_\_\_\_\_
A. uric acid 
B. urea 
C. ATP 
D. ammonia

Answer 2

A. uric acid

Question 3

An amino acid that breaks down to yield acetyl-CoA is called\_\_\_\_\_
  A. ketogenic 
  B. lipidogenic 
  C. alphaphilic 
  D. glucogenic

Answer 3

A. ketogenic

Question 4

In the global N cycle, N2 is reduced to ammonia by all of the following except \_\_\_\_\_
  A. Haber-Bosch reaction 
  B. ligtning strike 
  C. aminotransferase 
  D. nitrogenase

Answer 4

C. aminotransferase

Question 5

A common cofactor used in the synthesis of amino acids is \_\_\_\_\_\_\_\_\_\_\_
  A. pantothenic acid 
  B. lipoic acid 
  C. Tetrahydrofolate (THF) 
  D. thiamine

Answer 5

C. Tetrahydrofolate (THF)

Question 6

The cofactor used by most aminotransferases is \_\_\_\_\_\_\_\_\_\_\_\_\_
  A. ATP 
  B. Pyridoxial phosphate (PLP) 
  C. NADP+ 
  D. NAD+

Answer 6

B. Pyridoxial phosphate (PLP)

Question 7

In the nitrogenase catalyzed reduction of N2 to ammonia, \_\_\_\_\_\_\_\_\_\_ is a co-substrate.
  A. ATP 
  B. FADH2 
  C. NADH 
  D. CO2

Answer 7

A. ATP (Haber-Bosch Process takes lots of heat)

Question 8

A key N assimilation reaction is the conversion of alpha-ketoglutarate to \_\_\_\_\_\_\_\_
  A. uric acid 
  B. glutamate 
  C. urea 
  D. glutamine

Answer 8

B. glutamate