Metabolism and Biotransformation, Phase II

Question 1

What is a conjugation reaction?

Answer 1

Reaction of a phase 1 metabolite with a polar molecule to enhance solubility and aid in urinary excretion
- Exceptions: Acetylation and methylation

Question 2

Difference between Phase I and Phase II reactions?

Answer 2

Phase I reactions = rate limiting

Phase II reactions = faster

Question 3

General facts of Phase II?

Answer 3

Enzymes generally in cytosol
Reactions generally increase water solubility
- Exception: Methylation and acetylation

Question 4

Phase II reactions: solubilization/elimination types?*

Answer 4

1. .) Glucuronide conjugation (Glu)
2. ) Sulfate conjugation (SO4)
3. ) Glutathione conjugation (GSH)
4. ) Amino acid conjugation (Gly)
5. ) Acetylation (Acetyl)
6. ) Methylation (Methyl)