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

Answer: (A)

Krebs' cycle also know 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 a-ketoglutarate) and asparate (for oxaloacetate) after their deamination. Fats produce fatty acids and glycerol. Glycerol is phosphorylated and oxidised to form glyceraldehyde $3$-phosphate. Fatty acids undergo $\beta$-oxidation to produce acetyl $CoA$. Acetyl $CoA$ enters Krebs' cycle.