Amino Acid Metabolism

Question 1

overview of the fates of amino acids

Answer 1

–can be degraded to 7 dif molecules –are glucogenic if degraded into intermediates that can reform glucose –are ketogenic if degraded into intermediates of ketone body formation –but can also be both

Question 2

list all the fates of AA carbon skeletons

Answer 2

AA C skeleton converted to: glucogenic 1. pyruvate 2. oxaloacetate 3. a-ketoglutarate 4. succinyl-coA 5. fumarate ketogenic 6. acetyl-coA 7. acetoacetate

Question 3

list the glucogenic only amino acids (13)

Answer 3

alanine, arginine, asparagine, aspartate cysteine glycine, glutamate, glutamine histidine methionine proline serine valine

Question 4

list the ketogenic only amino acids (2)

Answer 4

leucine lysine

Question 5

list the glucogenic and ketogenic amino acids (5)

Answer 5

isoleucine phenylalanine threonine tryptophan tyrosine

Question 6

fate 1: amino acid carbon skeletons that are converted to pyruvate

Answer 6

1. serine — deaminated directly to pyruvate 2. threonine — deaminated and converted to glycine 3. glycine — THF-dependent rxn converts it to serine 4. alanine — SGPT exchanges it w/ pyruvate 5. cysteine — must be deaminated and desulfonated to form pyruvate

Question 7

fate 2: amino acid carbon skeletons converted to oxaloacetate

Answer 7

1. asparagine — deaminated first from the side chain to form NH4+ and aspartate 2. aspartate — exchanged w/ oxaloacetate by SGOT

Question 8

fate 3: amino acid carbon skeletons converted to a-ketoglutarate

Answer 8

1. glutamine — deaminated 1st from side chain to form NH4+ and glutamate 2. proline/arginine/histidine — converted to glutamate 3. glutamate — converted to a-ketoglutarate by glutamate dehydrogenase

Question 9

fate 4: amino acid carbon skeletons that are converted to succinyl-coA

Answer 9

methionine/valine/isoleucine — converted to propionyl-CoA in a B12-dependent pathway part of methionine’s conversion is thru SAM propionyl-CoA is converted to succinyl-CoA —used in fatty acid oxidation and in TCA cycle

Question 10

fate 5: amino acid carbon skeletons that are converted to fumarate

Answer 10

aspartate tyrosine phenylalanine

Question 11

fate 6: amino acid carbon skeletons that are converted to acetyl-CoA

Answer 11

leucine threonine isoleucine

Question 12

fate 7: amino acid carbon skeletons that are converted to acetoacetate

Answer 12

leucine, lysine tryptophan phenylalanine tyrosine