Question

In general, there is a positive change in free energy associated with reduction reactions, and most of them are coupled with oxidation reactions. The last step in the biosynthesis of cholesterol involves the reduction of a carbon-carbon double bond. What activated carrier molecule is used in this reaction (and generally for the reduction of lipids) and how would this reaction be influenced by the levels of available ATP?

Answer 1

NADPH is the activated carrier molecule used for lipid reduction and cholesterol biosynthesis. The reaction is influenced by ATP levels, with high levels of ATP facilitating the generation of NADPH for biosynthetic anabolic pathways.

Step-by-step explanation:

The activated carrier molecule used for the reduction of lipids and in the last step of biosynthesis of cholesterol is NADPH. This molecule provides the necessary reducing power for the reduction of the carbon-carbon double bond in cholesterol production.

The levels of available ATP influence this reaction because ATP is required for the generation of NADPH. ATP is consumed in the biosynthetic anabolic pathways that produce NADPH from NADP+, and a high amount of ATP signifies that the cell has sufficient energy to engage in anabolic processes like the synthesis of cholesterol. Conversely, low ATP levels would indicate a reduced capacity for such biosynthetic reactions.