Ketosis is a bodily state of elevated ketone bodies in the blood, formed by ketogenesis. Ketogenesis begins once the glycogen levels in the liver are depleted. Which of the following is the most likely source of ketone bodies formed after the depletion of liver glycogen stores? (A) blood glucose (B) brain tissue (C) muscle tissue (D) fatty acids

D. Fatty Acids

Explanation:

When fatty acids undergo beta-oxidation to serve as a source of ATPs, ketone bodies are produced. During starvation or medical conditions such as diabetes mellitus, carbohydrate supply to liver cells is depleted.

Once the stored glycogen has been depleted from the liver cells, the fatty acids are funneled into beta-oxidation to produce ATPs. The process also forms acetone, acetoacetate, and D-beta-hydroxybutyrate, that is the ketone bodies. The more the fatty acid molecules enter the beta oxidation, the more ketone bodies are produced.