Amino Acid Nitrogen Flashcards
What is the fate of most excess nitrogen?
it becomes urea
Fasting state - which two amino acids contribute to form glucose
alanine and glutamine
when muscle breaks down protein, most nitrogens come from
branched chains - valine, leucine, isoleucine.
Describe transamination reactions in general.
require PLP, use aminotransferases. more commonly needed for amino acid metabolism
Alanine transferase (ALT) give reactants and products
alanine turning into pyruvate
requires alpha ketoglutarate
Aspartate transaminase (AST)
aspartate turning into oxaloacetate, requires alpha ketoglutarate
Describe formation of PLP
pyradoxin, vitamin B6 starting material. oxidation of a primary alcohol into an aldehyde by a dehydrogenase. requires NAD+. Then a phosphate is transferred by a kinase.
What are two major carriers of nitrogen in the blood
alanine and glutamine
alpha amino acid becomes a keto acid; where does the oxygen come from?
water
alpha keto acid becomes alpha amino acid- where does the oxygen go?
goes to the water
branched-chain amino acid transaminase
branched chain amino acid plus alpha ketoglutarate becoming glutamate and branched chain ketoacid (3 different types of these). then those carbons can be used fuel - oxidize these branched chain keto acids.
works on all three branched chain amino acids.
glutamate dehydrogenase
glutamate getting oxidized into ammonia and alpha ketoglutarate using NADP+ or NAD+
glutamate synthetase
glutamate and ammonia ion with ATP becoming glutamine
glutaminase
glutamine + H2O becoming glutamate and ammonia ion. (for urea cycle)
Urea cycle - nitrogens show up as?
aspartate and ammonium ions
