Question

In the Calvin-Benson cycle, to produce 1 molecule of glyceraldehyde 3-phosphate by fixing 3 molecules of carbon dioxide, 9 molecules of ATP and ____ molecules (in integer) of NADPH are typically utilized.

Hint:

Understanding the input of ATP and NADPH in the Calvin cycle is fundamental in grasping how energy from sunlight is transformed into chemical energy stored in carbohydrates during photosynthesis.

Answer 1

The Calvin-Benson cycle, also known as the Calvin cycle or C3 cycle, is a series of biochemical redox reactions that take place in the stroma of chloroplasts in photosynthetic organisms. This cycle is crucial for carbon fixation, contributing to the synthesis of glucose. Biochemical Requirements:

• Each CO\(_2\) molecule fixed requires **3 ATP** and **2 NADPH** molecules.
• To fix **3 CO\(_2\)** molecules and produce one molecule of glyceraldehyde 3-phosphate, the cycle uses:

Step 1: ATP Requirement \[ 3 \times 3 \text{ ATP} = 9 \text{ ATP} \] Step 2: NADPH Requirement \[ 3 \times 2 \text{ NADPH} = 6 \text{ NADPH} \] Conclusion:

Explanation: Therefore, to synthesize **one molecule of glyceraldehyde 3-phosphate**, a total of **9 ATP** and **6 NADPH** molecules are consumed. This reflects the energy and reducing power required to incorporate three carbon atoms from CO\(_2\) into an organic molecule.