What is the primary role of HMG-CoA synthase in the body?

HMG-CoA synthase plays a crucial role in the synthesis of ketone bodies, particularly during periods of fasting or carbohydrate restriction. In these conditions, the liver converts excess acetyl-CoA, generated primarily from fatty acid oxidation, into ketone bodies, which serve as an alternative energy source for tissues like the brain.

The process begins with the condensation of acetyl-CoA and acetoacetyl-CoA to form HMG-CoA, catalyzed by HMG-CoA synthase. This step is essential in the overall pathway leading to the production of ketone bodies—acetoacetate, β-hydroxybutyrate, and acetone. These ketone bodies can then be released into the bloodstream and utilized by various tissues, especially when glucose availability is low.

While other options relate to lipid metabolism, they do not accurately describe the primary function of HMG-CoA synthase. Triglyceride synthesis and fatty acid oxidation are involved in energy storage and release, respectively, but they do not specifically require HMG-CoA synthase in their pathways. Cholesterol breakdown also does not involve this enzyme, as it is more relevant to cholesterol metabolism rather than the synthesis of ketone bodies. Therefore, HMG-Co