General Medicine General 1e7c7228 The first step in synthesis of steroids is derived from the cleavage of cholesterol. What is the enzyme responsible for the cleavage of 20,22-dehydrocholesterol to pregnenolone? A Delta 5-3 beta-hydroxysteroid dehydrogenase (3B - HSD) B HMG-CoA reductase C Aromatase D 17 alpha-hydroxylase