Detoxification in the Liver

Question 1

What are Xenobiotics?

Answer 1

Foreign substances which have no nutritional value, need to be excreted

Question 2

What do non-polar, non water-soluble xenobiotics require in order to be excreted?

Answer 2

2 phase Biotransformation

Question 3

What does the first phase involve of Biotransformation?

Answer 3

Addition of a functional group in order to produce a small increase in hydrohilicity

Question 4

What does Phase 2 of Biotransformation involve?

Answer 4

Conjugation of xenobiotic to produce hydrophilic metabolites and make a large increase in hydrophilicity

Question 5

3 examples of Conjugation molecules

Answer 5

Glucuronic acid
Sulfate
Glutathione

Question 6

Which causes a larger increase in Hydrophilicity? Phase 1 or 2 of Biotransformation

Answer 6

Phase 2

Question 7

What do
ADME
stand for in Pharmacokinetics?

Answer 7

Absorption
Distribution
Metabolism
Elimination

Question 8

What does CYP stand for? What are they and what phase of biotransformation are they required for?

Answer 8

Cytochrome-P450s
group of enzymes
Phase 1 ONLY

Question 9

What do CYPs contain which is useful for Phase 1 of Biotransformation?

Answer 9

Haem component- capable of oxidizing molecules

Question 10

What do CYPs use to reduce themselves in order to oxidise the Xenobiotic?

Answer 10

NADPH

Question 11

What does the reaction of CYPs and xenobiotic result in?

Answer 11

Water molecule and haem free radical

Question 12

Where does Detoxification occur?

Answer 12

Smooth ER (mostly in liver cells)