enzyme Flashcards
enzyme definition
a substance that increases the rate of a chemical reaction without itself being changed in the overall process
what is the Km or mechaelis-menten constant
substrate at which the reaction velocity is 50% of maximum
what does a high km indicate
weak affinity
what does a low km indicate
high affinity
where is ALP released from
intrahepatic or extrahepatic bile ducts, bone, placenta(last trimester), germ cell tumours, intestine
clinical approach to unexplained ALP
check LFTs, check vitamin D, ALP isoenzy,es
where is ALT released from
hepatic (hepatitis, alcohol), non alcoholic fatty liver disease, kidney, pancreatitis (amylase is better), MI (troponin is better)
where is gamma GT released from
hepatobiliary , enzyme inductions in alcoholics, rifampacin, phenytoin, phenobarbitone, pancrease, kidney
where is LDH released from
lymphoma, haemophysis, placenta (seminoma), myositis, liver injury, cardiac
where is serum amylase rleased from
pancrease salivary (mumps), benign macroamylase
what should you do if u suspect macroamylase
amylase electrophroresis
where is CK released from
skeletal muscle e..g rhabdomyolysis, cardiac muscle
where is troponin I released from
ACS, PE, MYOCARDITIC, CARDIOMYOPATHY, DISSECTION,
When does troponin return to normal
5-10days after chest pain
When does troponin peak
12 hours
