The upcoming discussion will update you about the differences between C3 Plants and C4 Plants.
C3 Plants:
1. Plants that carry out C3 cycle is known as C3 plants.
2. CO fixation occurs one time in mesophyll cell.
3. RuBP (5-C compound) is CO2 acceptor. It is a weak CO2 acceptor.
4. First product of CO2 fixation is PGA (3-C compound).
5. Leaf does not show Kranz anatomy.
6. Leaf with monomorphic chloroplasts.
7. Enzymes of Calvin cycle are found in all green cells.
8. Enzyme for carboxylation is RUBISCO.
9. Photorespiration occurs, oxygen functions as a inhibitor of photosynthesis.
10. CO2 compensation point is 100 ppm.
11. CO2: NADPH2: ATP = 6 : 12 :18
12. Productivity moderate.
13. Temperature tolerance is less.
14. Glucose synthesis in mesophyll cells.
15. Utilize low CO2, till it remains 50 – 100 ppm concentration in atmosphere.
16. Compensation point at high CO2 concentration.
17. C3 plants require 18 ATP for the synthesis of one mol of glucose.
C4 Plants:
1. Plants that carry out C4 cycle is known as C4 plants.
2. CO2 fixation occurs twice, one in mesophyll cells to form oxaloacetic acid (4C) and another in bundle sheath cells to form 3-phosphoglyceric acid (3C).
3. PEPA in mesophyll cells and RuBP in bundle sheath cells function as CO2 acceptor. PEPA is a very strong CO2 acceptor as compared to RuBP.
4. It is oxaloacetic acid (4-C compound) in mesophyll cells and PGA in bundle sheath cells.
5. Leaf with Kranz anatomy.
6. Leaf with dimorphic chloroplasts.
7. Enzymes of Calvin cycle are absent in mesophyll cells while present in bundle sheath cells.
8. Enzyme for carboxylation is PEP carboxylase (PEPCO).
9. Photorespiration is absent. There is no inhibitory effect of O2.
10. CO2 compensation point is 10 ppm.
11. CO2: NADPH2 : ATP = 6: 12: 30.
12. Twice as compared to C3 plants.
13. Temperature tolerance is good.
14. Glucose synthesis in bundle sheath cells.
15. Consume more CO2 till it remains 10 ppm concentration in atmosphere.
16. Compensation point at very low CO2 concentration.
17. C4 plants require 30 ATP to synthesize one glucose molecule.