We know that fatty acids are an important source of energy for tissues. List the ketone bodies and explain why fatty acids sometimes need to be converted to ketone bodies before they can be used. Briefly summarize the two main steps in ketone metabolism

Question

What will be an ideal response?

Answer 1

Answer: Ketone bodies, such as acetone, acetoacetate, and β-hydroxybutyrate, are an important source of fuel for tissues that cannot use fatty acids directly. For example, brains of mammals use glucose as an energy source however, under conditions of starvation, glucose levels are diminished. With little or no glucose available, the brain needs to obtain an alternative source of energy. Since the brain cannot use fatty acids directly, the liver converts the fatty acids to ketone bodies which are then delivered to the brain and oxidized.

Ketogenesis is the first step that synthesizes ketone bodies. In ketogenic tissues such as the liver, Acetyl CoA is converted into the ketone bodies, acetoacetate, and β-hydroxybutyrate. These ketone bodies travel via the blood and are taken up by the brain (ketolytic tissue) where through the process of ketolysis, Acetyl CoA is resynthesized.