Committed step in cholesterol biosynthesis CH2C- OH CH2C-SCoA O -OOC CH3 2 NADPH + 2H+ HMG-CoA-reductase ER 2 NADP + CoA lovastatin CH2C- OH CH2C- OH O -OOC CH3 mevalonate

Biosynthesis of cholesterol from mevalonate C10 C15 C30 squalene OH O -OOC CH2 C- CH2 C- OH mevalonate CH3 3 ATP 3 ADP + Pi + CO2 CH2 C- CH2 C- O-P-O-PO3-2 O CH3 3-isopentenylpyrophosphate C10 C15 C30 squalene

N.B. You are not required to know the structures of these steroids. You only need to know the structure of cholesterol. Adapted from Berg, Tymoczko and Stryer Biochemistry 5th ed.