Question

Krebs' cycle is also called metabolic sink as it is a common pathway for

• A. Carbohydrates, fats and proteins (amino acids)
• B. Carbohydrates and fats only
• C. Carbohydrates and organic acids only
• D. Proteins and fats only

Answer 1

The correct option is A Carbohydrates, fats and proteins (amino acids)

Krebs' cycle also known as TCA cycle or citric acid cycle, is a common pathway of oxidative breakdown of carbohydrates, fatty acids and amino acids. Amino acids enter the Krebs' cycle directly as glutamate (for $\alpha$-Ketoglutarate) and aspartate (for oxaloacetate) after their deamination. Fats produce fatty acids and glycerol. Glycerol is phosphorylated and oxidized to form glyceraldehyde 3-phosphate. Fatty acids undergo $\beta$-oxidation to produce acetyl CoA. Acetyl CoA enters Krebs' cycle.

So the correct answer is 'Carbohydrates, fats and proteins (amino acids)'.