Question

Give the schematic representation of an overall view of Krebs’ cycle.

Answer 1

Schematic representation of an overall view of Krebs’ cycle:

The Krebs’ cycle (also called the citric acid cycle or TCA cycle) is a cyclic sequence of enzyme-controlled reactions in which acetyl-CoA is completely oxidised to carbon dioxide. It takes place in the mitochondrial matrix.

---

Overall schematic pathway:

Acetyl-CoA (2C) 
+ Oxaloacetate (4C) 
↓ 
Citric acid / Citrate (6C) 
↓ 
Isocitrate (6C) 
↓ (CO₂ released, NADH formed) 
α-Ketoglutarate (5C) 
↓ (CO₂ released, NADH formed) 
Succinyl-CoA (4C) 
↓ (ATP / GTP formed) 
Succinate (4C) 
↓ (FADH₂ formed) 
Fumarate (4C) 
↓ 
Malate (4C) 
↓ (NADH formed) 
Oxaloacetate (4C) regenerated

---

Energy yield per acetyl-CoA:

• 3 NADH 
• 1 FADH₂ 
• 1 ATP (or GTP) 
• 2 CO₂

---

Schematic diagram of Krebs’ cycle:

---

Conclusion:

Thus, Krebs’ cycle is the central metabolic pathway that links carbohydrate, fat, and protein metabolism and plays a vital role in cellular energy production.