Question

Where does the light-independent reaction take place, what are the reactants and products?

A) The light-independent reaction (Calvin cycle) takes place in the stroma of chloroplasts. The reactants are carbon dioxide, ATP, and NADPH, and the products are glucose and ADP.

Answer 1

The light-independent reactions of photosynthesis, known as the Calvin cycle, occur in the stroma of chloroplasts and use carbon dioxide, ATP, and NADPH to produce glucose and regenerate ADP and NADP+.

Step-by-step explanation:

The light-independent reactions, also known as the Calvin cycle, take place in the stroma of chloroplasts. These reactions utilize the energy from ATP and NADPH, produced during the light-dependent reactions, to convert carbon dioxide (CO₂) into organic compounds.

Stages of the Calvin Cycle:

1. Fixation: CO₂ is attached to a five-carbon sugar called ribulose bisphosphate (RuBP). This step is facilitated by the enzyme ribulose-1,5-bisphosphate carboxylase/oxygenase, better known as RuBisCO.
2. Reduction: The compound is then reduced to glyceraldehyde-3-phosphate (G3P), also simply referred to as GA3P, using the energy from ATP and the reducing power of NADPH.
3. Regeneration: RuBP, the molecule that starts the cycle, is regenerated, allowing the process to continue.

As a result, the Calvin cycle transforms CO₂, along with the energy from ATP and NADPH, into GA3P, which can then be used to form glucose and other carbohydrates essential for the plant's energy needs and growth. The byproducts of this process are ADP and NADP+, which return to the light-dependent reactions to be re-energized.