The enzyme required for carboxylation in the Calvin cycle is

Core Logic

In the Calvin cycle, the fixation of 1 molecule of CO₂$CO_{2}$ requires 3 ATP and 2 NADPH molecules. To synthesize one complete molecule of glucose (a 6-carbon sugar), the cycle must turn 6 times to fix 6 molecules of CO₂$CO_{2}$.

Step 1: Calculation

Pattern Recognition

For 1 CO₂$CO_2$ = 3 ATP, 2 NADPH. For 1 Glucose (C₆$C_6$) = multiply by 6. Result: 18 ATP, 12 NADPH.

Chapter Mix

Class 11 Biology: Photosynthesis in Higher Plants

Core Logic

Let's analyze the statements:

• Statement A is incorrect. The water splitting complex (photolysis of water) is physically associated with PS II on the inner side of the thylakoid membrane, not PS I.
• Statement B is correct. The C₃$C_{3}$ pathway (Calvin cycle) is the main biosynthetic pathway for CO₂$CO_{2}$ fixation in ALL photosynthetic plants, including C₄$C_{4}$ plants (occurs in bundle sheath cells).
• Statement C is correct. C₄$C_{4}$ plants possess mechanisms that concentrate CO₂$CO_{2}$ at the RuBisCO enzyme site, suppressing the oxygenase activity and thus preventing photorespiration.
• Statement D is incorrect. It is the C₄$C_{4}$ plants that exhibit 'Kranz' anatomy (wreath-like arrangement of bundle sheath cells), not C₃$C_{3}$ plants.
• Statement E is correct. ATP synthesis in chloroplasts (photophosphorylation) operates via chemiosmosis.

Step 1: Final Conclusion

The incorrect statements are A and D.

Pattern Recognition

Water splitting = PS II (p680). Kranz anatomy = C₄$C_{4}$ hallmark. Statements A and D are fundamental inversions of core facts.

Chapter Mix

Class 11 Biology: Photosynthesis in Higher Plants