3.8 Cholesterol Metabolism

Question 1

Site of cholesterol synthesis

Answer 1

Cytosol

Question 2

Stages of cholesterol synthesis

Answer 2

Synthesis of mevalonate from acetyl CoA
Conversion of mevalonate to two activated isoprenes
Condensation of six isoprene units to form squalene
Formation of lanosterol
Formation of cholesterol

Question 3

Rate limiting step in cholesterol synthesis

Answer 3

Synthesis of mevalonate

Question 4

IPP and DPP condense to form ___ using the enzyme ___

Answer 4

Geranyl pyrophosphate using diemthlallyl transferase

Question 5

a second moelcule of IPP condense with GPP to form ___ using ___

Answer 5

Farnesyl pyrophosphate using dimethylallyl transferase

Question 6

Squalene is formed by

Answer 6

2 molecules of FPP condensing and being reduced via NADPH dependent squalene synthase

Question 7

Enzyme for the formation of lanosterol from squalene

Answer 7

Oxidosqualene” lanosterol cyclase

Question 8

Principal sterol in the feces

Answer 8

Co-prostanol