AA Catabolism- Brar

Question 1

What AAs are ketogenic ONLY (2)?

Answer 1

Leucine and Lysine

Question 2

What AAs are glucogenic and ketogenic (4)?

Answer 2

Tyrosine, Isoleucine, Phenylalanine, and Tryptophan

Question 3

What AAs form pyruvate (6)?

Answer 3

1. Serine and threonine → pyruvate.
2. Glycine → serine → pyruvate.
3. Tryptophan → alanine → pyruvate.
4. Cysteine → pyruvate
   (See, There Goes The Crying Asian Pirate (pirate to remember it’s pyruvate))

Question 4

What AAs form Fumarate (3)?

Answer 4

1. Phenylalanine → tyrosine → fumarate
2. Aspartate → fumarate
   (PAT)

Question 5

What AAs form Oxaloacetate (2)?

Answer 5

1. Aspartate → oxaloacetate

2. Asparagine → asparate + NH+4 → Oxaloacetate

Question 6

What AAs form Succinyl-CoA (4)?

Answer 6

Methionine, Valine, threonine and Isoleucine.
(TIM V SUCks CoA)
(Methionine is the precursor for S-Adenosylmethionine (SAM))

Question 7

What AAs form Acetyl CoA?

Answer 7

Isoleucine, Leucine and tryptophan

LIT

Question 8

What AAs form Acetoacetyl CoA (5)?

Answer 8

Leucine, Lysine, Phenylalanine, Tryptophan and Tyrosine

Question 9

What AAs form alpha-ketoglutarate (5)?

Answer 9

Proline, Arginine, Histidine and glutamine → glutamate → α-ketoglutarate

Question 10

What role does folic acid (vitamin B9) play in AA metabolism?

Answer 10

Tetrahydrofolate receives one carbon fragments from donors such as serine, glycine, and histidine and transfers them to intermediates in the synthesis of amino acids, purines, and thymidine monophosphate (TMP), a pyrimidine nucleotide found in DNA.