Md2 Block4 Biochem L 39 Metabolism Of Amino Acids Carbon Skeleton Part A

Front 1

catabolism of 20 amino acids proceeds by removal of NH3 followed by breakdown of C-skeleton

7 products formed:

Back 1

-pyruvate
-acetyl CoA
----> -acetoacetyl CoA
-ketogluarate
-succinyl CoA
-fumarate
-OAA (oxyloacetate)

Hint 1

Front 2

Amino acids are classified as

Back 2

ketogenic
or
glucogenic

Glucogenic amino acids can be used to synthesize glucose via gluconeogenesis.

Hint 2

Front 3

Ketogenic amino acids can be converted to =

Back 3

acetyl CoA
or
acetoacetyl CoA

Front 4

essential amino acids =

nonessential amino acids =

Back 4

not synthesized in humans

synthesized in humans

Hint 4

Front 5

Arginine is only essential in _____

(urea cycle is less active in ___ compared to adults).

Back 5

children

children

Hint 5

Front 6

Amino acids that form oxaloacetate

Back 6

Asn hydrolyzed by asparaginase  NH3 and Asp

Aspartate ----> OAA by transamination

Hint 6

Front 7

Amino acids that form a-KG
1. Glutamine

Back 7

Glutamine ----> glutamate and NH3 by glutaminase

Glutamate ----> -KG by transamination or through oxidative deamination by glutamate dehydrogenase

Hint 7

Front 8

Amino acids that form a-KG

2. Proline

Back 8

Proline oxidized to
1-pyrroline 5 carboxylate ----> oxidized to glutamate

Glutamate ----> transamination or oxidative deamination

Hint 8

Front 9

Amino acids that form a-KG
3. Arginine

Back 9

Arginine cleaved by arginase  ornithine (urea cycle reaction)

Ornithine ----> transamination 
Glutamate 5-semialdehyde  -KG

Hint 9

Front 10

Amino acids that form a-KG

4: Histidine 

Back 10

deaminated N-formiminoglutamate (FIGlu) donates formimino group to tetrahydrofolate leaving glutamate

Hint 10

Front 11

Amino acids that form a-KG

Individuals deficient in folic acid show  [FIGlu] in urine after ingestion of large dose of His

Back 11

FIGlu excretion test used for diagnosing deficiency of folic acid


Histidinemia due to histidinase deficiency