Biosynthesis of Cholesterol 27 



and my own have shown some time ago, that acetone is metabolized 

 via acetate. If, however, you do the same experiment \Wth carbonyl 

 labelled acetoacetate the dilution is only about 2. Curran is inclined to 

 believe that the utilization of acetoacetate goes by two pathways: one 

 through acetate, and another pathway through acetoacetate. This 

 raises the possibility that the biosynthesis of cholesterol goes by a 

 mechanism in which the acetoacetate is used to form the beginning 

 of the molecule, and then repeated additions of acetate complete the 

 synthesis. 



