Biotransformation II -Phase II Flashcards
three results form phase II conjugation
large increase in hydrophilicity
increase in molecular weight
detoxification of activated metabolites
three examples to increase the hydrophilicity
glucuronidation
sulfation
glutathione conjugation
two examples of increase in molecular weight
glucuronidation
glutathione
two examples that detox activated metabolites but don’t increase the hydrophilicity
acetylation
methylation
cofactor for glucuronidation
UDPGA
enzyme for glucuronidation
UGT
where does glucuronidation take place
inside the ER
what organ does glucuronidation take place in
liver mostly
substrates for glucuronidation
nucleophilic herteroatoms (O,N,S)
used to donate groups to compounds to increase molecular weight and hydrophilicity
cofactors
cofactors are ____
high energy compounds
endogenous substrates
bilirubin
steroid hormones
thyroid hormones
bile acids
compounds less than 300 are excreted in
urine
compounds more than 300 are excreted in
bile
multiple isoforms of UGT
UGT1
UGT2
complete individual genes for each isoform, separate locus
UGT2
alternative splicing on one gene locus
UGT1
Beta-glucuronidase can
chop off the sugar from a compound and lead to entrohepatic cycling or make hormones active again
a series of enzyme catalyzed processes that alters the physiochemical properties of foreign chemicals from those that favor absorption across biological membranes to those favoring elimination in urine or bile
xenobiotic transformation
biotransformation of xenobiotics is catalyzed by various enzymes and divided into four categories
- hydrolysis
- reduction
- oxidation
- conjugation
in general, individual xenobiotic-biotransforming enzymes are located….
in a single organelle
