5.1.4 Using the Products of the Light Dependent Reaction

1. ATP (Adenosine Triphosphate)
2. Reduced NADP (NADPH) These products are used in the light-independent reaction (Calvin Cycle) to synthesise organic molecules such as glucose.

Key Products and Their Uses

1. ATP:

• Provides energy for the conversion of glycerate-3-phosphate (GP) into triose phosphate (TP) during the Calvin Cycle.
• Used to regenerate ribulose bisphosphate (RuBP) from triose phosphate, ensuring the cycle can continue.

2. Reduced NADP (NADPH):

• Acts as a reducing agent in the Calvin Cycle.
• Transfers hydrogen ions to glycerate-3-phosphate (GP), reducing it to triose phosphate (TP).

Connection Between Light-Dependent and Light-Independent Reactions

• The light-dependent reaction generates energy-rich molecules (ATP and NADPH) required to fix carbon dioxide into carbohydrates.
• Without these products, the Calvin Cycle cannot proceed, halting the production of essential organic compounds.