Staing point of ketone body synthesis –
**Core Concept**
The synthesis of ketone bodies is a critical process that occurs in the liver, particularly in states of low glucose availability or fasting. It involves the breakdown of fatty acids to produce ketone bodies, which can serve as an alternative energy source for various tissues.
**Why the Correct Answer is Right**
Ketone body synthesis begins in the mitochondria of liver cells. When the liver's glucose stores are depleted, the enzyme **HMG-CoA synthase** is activated, and it catalyzes the condensation of **acetyl-CoA** and **oxaloacetate** to form 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA). This is the first step in the production of ketone bodies, including **acetoacetate**, **β-hydroxybutyrate**, and **acetone**.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is not relevant to the synthesis of ketone bodies.
**Option B:** This option is incorrect because it does not specify the enzyme responsible for the initial step of ketone body synthesis.
**Option C:** This option is incorrect because it does not accurately describe the first step in ketone body synthesis.
**Clinical Pearl / High-Yield Fact**
In diabetic ketoacidosis, the accumulation of ketone bodies can lead to metabolic acidosis, which is a life-threatening complication. Monitoring ketone body levels and adjusting treatment accordingly is crucial in managing this condition.
**Correct Answer: B. HMG-CoA synthase**