inter-organ flow of amino acids Flashcards
what happens to NH3 in extrahepatic (not liver) tissues?
NH3 combines with glutamate to form glutamine
what catalyzes this reaction: NH3 + glutamate= glutamine
glutamine synthetase (requires ATP and Mg2+)
what enzyme catbolizes glutamine?
glutaminase
during what state does liver glutaminase increase and NH3 is produced?
in the absorptive state
in what conditions does renal (kidney) glutaminase increase?
in acidotic conditions
what is another amino acid that is important for transporting amino groups between tissues?
alanine
which 6 amino acids are catabolized in the skeletal muscles?
- aspartate
- asparagine
- glutamate
- leucine
- isoleucine
- valine
V-I-L-A-A-G
what enzymes do muscles posses?
branched-chain aminotransferases (transaminases)
what type of amino acids are oxidized in the muscles ?
transaminated branched amino acids
what amino acid is produced in large quantities in the muscles?
Glutamine
what is used in the muscles for energy source for contracting muscles ? (hint: it is made in the kidneys and liver from 2 amino acids)
Creatine (made in kidneys and liver from Arg & Gly)
what are creatine and creatin phosphorus converted to ? where is this secreted?
Creatinine –> secreted in urine
which amino acids are metabolized in the kidneys?
glycine, alanine, glutamine, phenyalanine, & aspartate
P-A-A-G-G
kidenys are a major site for synthesis of what amino acids?
arginine, histidine, serine
what does ammonia generated from glutamine do in the kidneys?
deamination –> helps normalize blood pH
