Which of the following is link between carbohydrate and fat metabolism ?

Options

A. `CO_(2)`
B. Acetyl Co-A
C. Pyruvic acid
D. Citric acid

Answer

To determine the link between carbohydrate and fat metabolism, we need to analyze the metabolic pathways involved in both processes. Here’s a step-by-step breakdown:

### Step 1: Understand Carbohydrate Metabolism
- Carbohydrates, particularly glucose (a hexose), undergo glycolysis, where they are broken down into two molecules of pyruvic acid.

### Step 2: Conversion of Pyruvic Acid
- The pyruvic acid produced from glycolysis is then subjected to oxidative decarboxylation. This process removes a carbon dioxide molecule from pyruvic acid, converting it into acetyl-CoA.

### Step 3: Role of Acetyl-CoA
- Acetyl-CoA is a crucial metabolic intermediate. It enters the Krebs cycle (also known as the citric acid cycle) for further oxidation to produce energy.

### Step 4: Understand Fat Metabolism
- In fat metabolism, long-chain fatty acids undergo a process called beta-oxidation. During this process, fatty acids are broken down into two-carbon units, which are also converted into acetyl-CoA.

### Step 5: Linking Carbohydrate and Fat Metabolism
- Both carbohydrate metabolism (through pyruvic acid) and fat metabolism (through fatty acid oxidation) converge at acetyl-CoA. This makes acetyl-CoA the key link between the two metabolic pathways.

### Conclusion
- Therefore, the correct answer to the question is **acetyl-CoA** as it serves as the common intermediate in both carbohydrate and fat metabolism.

---