LECTURE 28 - AMINO REACTIONS Flashcards
a loss of function mutation in which enzymes may cause delayed absorption of dietary AAs in the GI tract?
chymotrypsin from pancreas
carboxypeptidase A, small intestine, non specific
pepsin
what is the difference between synthase vs synthetase
synthase: no ATP
synthetase: uses ATP
what reaction does glutamine synthetase do?
turns glutamate into glutamyl phosphate
high Energy intermediate, uses an ATP
uses an NH3 from AA breakdown to make glutamine
happens in various tissues
what reaction does glutaminase do?
takes glutamine and makes glutamate
release of NH4+, which will go into the urea cycle
happens in the liver
characteristics of the deamination of glutamine
happens in the liver and in the kidney but minor
deamination of glutamine gives glutamate
the consumption of NH4 by the urea cycle drives the reaction forward
the NH3 from the side chain is taken away
characteristics of deamination of glutamate and how is it regulated?
what is the principle of a transamination reaction?
take an amino acid from the group of one molecule and put it on another molecule
amino acid+ketoacid–> ketoacid+amino acid
happens in the organs
what are transamination pairs
all PLP dependent transamination reactions
which co-factor is required in transamination reactions?
pyridoxal phosphate (vitamin B6)
what do transaminases/aminotransferases do and what do they require?
transfer an amino group from one amino acid to a keto acid
generates a new set of amino acid+keto acid
all transaminases have PLP as their coenzyme (prosthetic group)
what is PLP?
pyridoxal phosphate
derived from vitamin B6
PLP is turned into pyridoxamine 5’ phosphate (PMP) by transamination
involved in a wide variety of reactions
what are key components of PLP
how does the ping pong mechanism of transamination work
most transaminases prefer alpha KG as the keto acid #2
schiff base intermediate
no ternary complex is formed
what is type II tyrosinemia
what is the glucose alanine “cahill cycle”
this cycle regenerates alanine in the muscle to make glucose in the liver
difference between ALT 2 and ALT1?
what are fates of the amino group on the amino acids?
