Difference between Glycolysis and Krebs Cycle

The upcoming discussion will update you about the differences between Glycolysis and Krebs Cycle.

Difference # Glycolysis:

1. It occurs inside the cytoplasm.

2. It is a straight or linear pathway.

3. Glycolysis is the first step of respiration in which glucose is broken down to the level of pyruvate.

4. The process is common to both aerobic and anaerobic modes of respiration.

5. It degrades a molecule of glucose into two molecules of an organic substance, pyruvate.

6. Glycolysis consumes 2 ATP molecules for the initial phosphorylation of substrate molecule.

7. In glycolysis, one glucose molecule liberates 4 ATP molecules through substrate level phosphorylation.

8. Net gain is two molecules of NADH and two molecules of ATP tor every molecule of glucose broken down.

9. The net gain of energy is equal to 8 ATP.

10. No carbon dioxide is evolved in glycolysis.

11. It is not connected with oxidative phos­phorylation.

12. Oxygen is not required for glycolysis.

Difference # Krebs Cycle:

1. Krebs cycle operates inside mitochondria.

2. It is a cyclic pathway.

3. Krebs cycle is the second step in respiration where an active acetyl group is broken down completely.

4. It occurs only in aerobic respiration.

5. It degrades pyruvate completely into in­organic substances (CO₂ + H₂O).

6. It does not consume ATP.

7. In Krebs cycle, two acetyl residues liberate two ATP or GTP molecules through substrate level phosphorylation.

8. Krebs cycle produces six molecules of NADH, and 2 molecules of FADH₂ for every two molecules of Acetyl Co A oxidized by it. Two molecules of NADH are liberated during conversion of two pyruvates to Acetyl CoA.

9. The net gain of energy is equal to 24 molecules of ATP. Six molecules of ATP can be produced from 2NADH₂ formed during dehydrogenation of two pyruvates.

10. Carbon dioxide is evolved in Krebs cycle.

11. Krebs cycle is connected with oxidative phosphorylation.

12. Krebs cycle uses oxygen as terminal oxidant.