# Without the light-dependent reactions of photosynthesis, the Calvin-Benson cycle would not be possible because it would lack what molecules?

May 12, 2018

Calvin-Benson cycle would not be possible without the light dependent reactions because it would lack ATP and $N A D P H 2$ molecules.

#### Explanation:

Photosynthesis occurs in 2 steps:
1. Hill's reaction or Light reaction
2. Dark reaction or Blackmann's reaction.

Light reaction occurs in presence of light in which solar energy is converted into chemical energy in form of ATP molecules and reducing power $N A D P H 2$ . Oxygen is liberated due to photolysis of water.

Dark reaction simply involves reduction of $C O 2$ into glucose ( $C 6 H 12 O 6$) in a series of reactions that constitute Calvin-Benson cycle.

Dark reaction can occur irrespective of the presence of light, but is dependent upon the end products of the light reaction. ATP and $N A D P H 2$ molecules produced during light reaction are used in different reactions of Calvin-Benson cycle.