Final: amino acid metabolism Flashcards
what do amino acids make?
protein
essential amino acids
obtained from dietary sources of protein
non-essential amino acids
made in our body
after a large meal
protein broken into amino acids
amino acids used as building blocks in protein synthesis
why do cells need to make use of amino acids?
ammonia (amine group) can become toxic if it is freed and builds up
how do we get rid of ammonia?
ammonia must be removed, sent to liver to be metabolized into a less toxic molec: urea
what enzyme transfer amino group from amino acids to keto acids
transaminases/aminotransferases
reversible
what do transamination reactions require?
pyridoxine (Vitamin B6) as a cofactor
alanine transamination
in a muscle cell
alanine transaminase (ALT) switches amino group on alanine with oxygen on alpha-ketoglutarate
results in pyruvate (with oxygen group) and glutamate (with amino group)
what do we do with pyruvate? (option 1)
pyruvate dehydrogenase converts pyruvate to acetyl-CoA
acetyl-CoA can enter citric acid cycle
what do we do with pyruvate? (option 2)
1) lactate dehydrogenase converts pyruvate to lactate which then travels to the liver
gluconeogenesis or glycolysis
make acetyl-CoA and ATP
how does glutamate get away with not transferring its amine group to another molecule?
it undergoes oxidative deamination
oxidative deamination where does it occur
glutamate travels to liver mitochondria bc free ammonia in cytoplasm is harmful
glucogenic amino acids
serve as substrates to make new glucose
EX: alanine, glycine
ketogenic amino acids
form ketone bodies
EX: leucine, lysine
