Question

What type of changes takes place in dark reaction?

Answer 1

1. Dark Reaction is the second step in the process of photosynthesis.
2. The chemical processes of photosynthesis occurring in the phase independent of light is called dark reaction.
3. It takes place in the stroma of the chloroplast.
4. The Dark reaction of photosynthesis is purely enzymatic and it is slower than the light reaction.

In dark reactions, two types of cyclic reaction occur. They are

1. Calvin cycle or C3 Cycle.
2. Hatch Slack Cycle or C4 cycle.

In dark reaction, sugars are synthesized from CO2. The energy poor carbon dioxide is fixed to energy rich carbohydrates using the energy rich compound ATP and the assimilatory power NADPH2 of light reaction. This process is called carbon fixation.

Blackman had first demonstrated the existence of dark reaction. Hence it is known as Blackman’s reaction.