AA Carbon skeleton metabolism Flashcards
What amino acids can be broken down to make pyruvate?
Alanine
Cysteine
Glycine
Serine
Threonine
Tryptophan
What amino acids converge at pyruvate?
Glutamine
Proline
Arginine
Histidine
How is histidine metabolized to glutamate?
Oxidized then de-cyclized
What are Methionine, valine, and isoleucine metabolized to?
Succinyl CoA
What are two important intermediates during the breakdown of methionine?
S-Adenosylmethionine (SAMe)
Homocysteine
What is the function of mitochondrial branched-chain a-keto acid dehydrogenase complex?
Catalyzes the final steps in catabolism of valine, leucine, and isoleucine
Similar to pyruvate dehydrogenase complex
What is the cause and symptoms of maple syrup disease?
Deficiency in branched-chain a-keto acid dehydrogenase complex.
Amino and keto acids accumulate in the blood and urine
Causes mental and physical deficits
What is required for the breakdown of Tryptophan, Tyrosine, and Phenylalanine?
Oxygenases
What cofactor is required for phenylalanine hydroxylase?
Tetrahydropbiopterin
What is Alcaptonuria?
Defect in oxidase in Phenylalanine/tyrosine catabolism
Accumulation of homogentisate, turns color when exposed to air
Treated with dietary restriction of Phe and Tyr and large doses of ascorbic acid
What is Phenylketonuria?
Deficiency of Phenylalanine hydroxylase
Accumulation of Phe
Causes severe mental retardation, treated with Phe restricted diet
What is Citrullinema caused by?
Deficiency in Arginosuccinate lyase
Causes lethergy, siezures, reduced muscle tension
