Question

Name two stages in photosynthesis?

Answer 1

Photosynthesis takes place in two stages.
1) Light reaction ( light dependent reaction)
2) Dark reaction (light independent reaction)

Light reaction takes place in the the thylakoids in the presence of light to make ATP and NADPH. The sunlight is changed into chemical energy.
Dark reaction takes place in the stoma of chloroplast and carbon dioxide becomes sugar with ATP and NADPH in a process called Calvin cycle or carbon fixation.

Answer 2

$\textbf{Photosynthesis}$:

6CO2 + 12H2O --chlorophyll,sunlight--> C6H1206 + 6O2 + 6H2O

It is the process by which green plants and some other organisms uses sunlight to synthesise nutrients from carbon dioxide and water. The main products forms here is glucose and by products are carbon dioxide and oxygen and water where which chlorophylls are the sites of photosynthesis.

Events occurring during Photosynthesis are as follows :

1. Absorption of light energy by chlorophyll.

2. Conversion of light energy to chemical energy and splitting of water molecules into hydrogen and oxygen.

3. Reduction of carbon dioxide to carbohydrates.

Stages of Photosynthesis are as follows :

1. $\textbf{Light Reaction }$:

It occurs in the Grana where photon are absorbed so as to excite electrons of chlorophyll to a higher energy level. These activated electrons are harnessed to form ATP from ADP and reduce NADP to NADPH. Water is also splitted during this and oxygen is released.

2. $\textbf{Dark Reactions }$:

Calvin cycle occurring in chlorophyll here carbon dioxide combined with 5-carbon sugar call ribulose biphosphate. This unstable compound breaks down into three carbon compounds (phosphoglyeric acid) this then forms glucose.