Find the incorrect statement(s) about photosynthesis from the following: A. The water splitting complex is associated with PS I. B. C₄$C_{4}$ plants use the C₃$C_{3}$ pathway of CO₂$CO_{2}$ fixation as the main biosynthetic pathway. C. In C₄$C_{4}$ plants, photorespiration does not occur. D. C₃$C_{3}$ plants exhibit 'Kranz' anatomy. E. ATP synthesis in chloroplast occurs through chemiosmosis. Choose the answer from the options given below:

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

The Calvin cycle (C3 pathway) begins with the carboxylation of Ribulose-1,5-bisphosphate (RuBP). This crucial step is catalyzed by the enzyme RuBP carboxylase-oxygenase, commonly known as RuBisCO. It fixes atmospheric CO₂$CO_{2}$ into a stable organic intermediate.

Step 1: Analyzing Other Options

• PEP carboxylase is the primary carboxylation enzyme in the C₄$C_{4}$ pathway.
• Carboxypeptidase is a digestive enzyme.
• Hexokinase is involved in the first step of glycolysis.

Step 2: Final Conclusion

The required enzyme is RuBP carboxylase-oxygenase (RuBisCO).

Pattern Recognition

Calvin cycle carboxylation = RuBisCO. Hatch-Slack (C₄$C_4$) carboxylation = PEPcase.

Chapter Mix

Class 11 Biology: Photosynthesis in Higher Plants