GI Liver Detoxication Flashcards
What is a xenobiotic?
A foreign substance that is not meant to be in the body.
What is an exogenous xenobiotic?
Ingested by not meant to be there e.g. pollutants in water.
What is an endogenous xenobiotic?
Things created by the body that arnt meant to be there like urea.
What is oxidation?
Removal of electrons from a species or adding oxygen.
What is reduction?
Gain of electrons or loss of oxygen.
What is hydrolysis?
Chemical breakdown of a compound due to a reaction with water.
What is glucoronidation?
Transfer of the glucuronic acid component of uridine diphosphate glucuronic acid to a substrate by any UDP-glucuronosyltransferase. Makes substances more water soluble e.g. for xenobiotics to make it easier to excreate or to hormones to make them be able to travel in blood.
How many stages are there in biotransformation in drug metabolism?
3 phases.
What occurs in phase 1 of biotransformation reactions?
Rendering a substance more water soluble by adding polar groups can be by hydrolysis, oxidation, reduction, hydrolysis, cyclization or decyclization.
What occurs in phase 2 of biotransformation reactions?
Conjugation with endogenous molecules increasing hydrophilicity.
What occurs in phase 3 of biotransformation reactions?
Excretion.
What is cytochrome p450 and what is its role in drug metabolism?
An enzyme that catalyses phase 1 reactions in liver detoxification.
Where is cytochrome p450 found?
In all of the body but in higher conc in liver.
