About photosynthesis process by Badshah Javed.

    ******Photosynthesis process******

The term ''photosynthesis" is originated from the two Greek word (photo=light, synthesis =combining.).

        Main events during photosynthesis.

1.Carbon dioxide from the atmosphere enters into the leaves through stomata.

2.Water from the soil is taken up by the roots and it sent to the leaves by xylem and is distributed to mesophyll cells.

3.Sunlight is trapped by chlorophyll which are present inside the chloroplast of the mesophyll cells.

4.Solar energy causes the photolysis of water.

That is. 
   
               2H2O----- 4H+  + O2 liberated  (Oxygen ).

5.Hydrogen ions from water combine with carbon dioxide and form glucose.

6.Oxygen gas is given out as a  by-product.

7.Solar energy is converted into utilisable chemical energy(ATP) which involves in the formation of glucose (Carbon dioxide ).

****** SITE OF PHOTOSYNTHESIS ******

Chloroplast is the site of photosynthesis. These are mainly found in the mesophyll cells of the leaves that are located between upper and lower epidermis of the leaf. They are also present in the guard cells of stomata.
Chloroplast are disc-shaped cell organelles. They appear green due to the presence of green colour pigment chlorophyll which are responsible for the trapped light energy from the sun essential for photosynthesis process. It  is found in the thylakoid membrane of the chloroplast. 

There are two phases which are involved in photosynthesis process.

1.Light reaction or photochemical phase.

2.Dark reaction or biosynthetic phase.

                Photochemical phase.

Biosynthetic phase of photosynthesis process is completed in grana lamellae.
During this phase hydrogen ions are released by the photolysis of water and solar energy is converted into ATP. Both H+ ions and ATP are used during biosynthetic phase.

                Biosynthetic phase.

Biosynthetic phase takes place in the stroma of chloroplasts. It does not need light energy. In this process carbon dioxide is reduced to glucose with the help of hydrogen ions which are produced during the photochemical phase. In this phase the needed energy is taken from the ATP which are generated  during the photochemical  phase.

      ******THANKS FOR READ ******
                   

Written by :Mohammad Javed.