Which of the following process does not happen during the light reaction of photosynthesis?

The correct answer is the reduction of carbon-di-oxide.

Concept:

• Photosynthesis is the process by which all green plants, some bacteria, and some protists (Euglena) use energy from sunlight to produce sugar, which through cellular respiration produces ATP, the fuel used by all living organisms.
• Photosynthesis occurs in the chloroplast of the cell.
• The reaction of Photosynthesis is commonly written as:
  • 6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂.
• The process of Photosynthesis takes place in two steps:
  • Light Reaction (Photochemical phase)
  • Dark Reaction (Biosynthetic phase)

Explanation:

Light Reaction:

• Light Reaction takes place only in the presence of light.
• The light reaction takes place in the thylakoid membranes.
• Light is absorbed in the light reaction, and energy is used to drive electrons from water to generate NADPH and protons across the membrane.
• The following major events occur during the light reaction of photosynthesis:
• Photolysis of water: 
  • In this water splits into protons, electrons and oxygen and produces NADPH and ATP.
• Photophosphorylation: 
  • Photophosphorylation is the process through which, ATP is synthesized from ADP and inorganic phosphate (P) by the cell organelles (like mitochondria and chloroplast).
• Reduction of NADP:
  • NADP is a reduced in the photosynthesis light reactions that is consumed in the Calvin cycle and used in many other anabolic reactions in both plants and animals.

Additional InformationDifference between Light reaction and Dark reaction: