3 Biology -- Respiration

Difference between oxidative phosphorylation and photophosphorylation.

1 Answers

Oxidative phosphorylation	Photophosphorylation
1. It takes place during aerobic respiration in inner membrane of mitochondria.	1. It takes place during photosynthesis in thylakoid.
2. It is independent of light.	2. It is dependent on light.
3. Oxygen is necessary.	3. Oxygen is not necessary.
4. Ultimate source of energy is respiratory substrate.	4. Ultimate source of energy for photophosphorylation is light.
5. In oxidative phosphorylation, the released hydrogen is accepted by NAD and FAD.	5. In photophosphorylation, the released hydrogen is accepted by NADP.

Fig 1- Oxidative phosphorylation

Fig 2- Photophosphorylation

Difference between aerobic and anaerobic respiration.

Aerobic respiration	Anaerobic respiration
1. O2 is utilized for breaking the respiratory substance into simple substrate.	1. O2 is not utilized for breaking the respiratory substance into simple substrate.
2. Respiratory substrate is completely oxidized.	2. Respiratory substance is incompletely broken down.
3. 38 ATP molecules are released.	3. 2 ATP molecules are released.
4. It takes place in cytoplasm and mitochondria.	4. It takes place only in cytoplasm.
5. It occurs in most...

Mention significance of Krebs cycle.

The significance of Krebs cycle are ;

1. Oxidative breakdown of carbohydrates, fatty acids and amino acids.

2. Oxaloacetic acid is utilized for formation of tyrimidines.

3. Explains the process of breaking of pyruvate into CO2 and water.

4. Energy is produced , stored and transported as ATP or GTP.

5. Synthesis of reduced coenzymes (FADH₂) and (NADH2) and controlled release of energy.

What is Krebs cycle? Show schematic representation of Krebs cycle.

Krebs cycle includes series of reactions through which acetyl COA produced in oxidative decarboxylation of pyruvic acid is completely broken down to CO2 and H2O with uptake of O2 ands release energy in form of ATP. Krebs cycle is also called as citric acid cycle or tricarboxylic acid (TCA) cycle.

Difference between glycolysis and Krebs cycle.

Glycolysis	Krebs cycle
1. It occurs in cytoplasm.	1. It takes place in mitochondria.
2. It is common to both aerobic and anaerobic respiration.	2. It occurs only in aerobic respiration.
3. It is a linear pathway.	3. It is cyclic pathway.
4. Carbon dioxide is not produced.	4. Carbon dioxide is produced.
5. It produces 2NADH₂ molecules per glucose molecules.	5. 6NADH₂ and 2FADH₂molecules are produced from two molecules of acetyl CoA.