Toxicology Flashcards
(16 cards)
What is the role of Epoxide hydrolase in xenobiotic defense?
Phase 2 conjugation
What is the role of UDP-glucuronosyltransferase in xenobiotic defense?
Phase 2 conjugation
What is the role of Catalase in xenobiotic defense?
Defence against reactive oxygen species (ROS)
What is the role of Cytochrome P450 in xenobiotic defense?
Phase 1 modification
What is the role of Alcohol dehydrogenase in xenobiotic defense?
Phase 1 modification
What is the role of N-acetyltransferases in xenobiotic defense?
Phase 2 conjugation
What is the role of Glutathione reductase in xenobiotic defense?
Defence against reactive oxygen species (ROS)
what does ADME stand for
Absorption, Distribution, Metabolism, Elimination
Which enzyme is not directly involved in phase I detoxification but is crucial for the function of key phase I enzymes?
Cytochrome P450 reductase (CPR).
Which compounds play a role in the defence against xenobiotics during phase I metabolism?
NADPH
NAD+
Oxygen
Which compounds play a role in the defence against xenobiotics during phase II metabolism?
Uridine diphosphate glucuronic acid (UDP-glucuronic acid)
3’-phosphoadenosine-5’-phosphosulfate (PAPS)
Acetyl-CoA
Reduced glutathione
Which compounds play a role in the defence against reactive oxygen species (ROS)?
NADPH
Vitamin E
Vitamin C
Reduced glutathione
What is the most likely final outcome of benzo[a]pyrene metabolism leading to reactive intermediates in cells?
Mutation, due to DNA binding by reactive metabolites formed during phase I and II detoxification.
what is the action of phase 1
Introduces or exposes functional groups (e.g., –OH, –NH2, –SH) to make xenobiotics more polar.
This can sometimes produce reactive intermediates, which may be more toxic.
what is the action of phase 2
conjugates (links) the xenobiotic or its Phase I product with molecules like glutathione, sulfate, or glucuronic acid to increase water solubility and promote excretion.
what is the action of phase 3
Actively pumps xenobiotics and their metabolites out of cells into bile, urine, or the intestinal lumen for elimination.
