Question

Where does the oxygen come from, when it is liberated during photosynthesis?

Answer 1

Hint: Photosynthesis can be divided into two stages- the light dependent reaction and the light independent reaction. Oxygen atoms are created during the light reaction process of photosynthesis, and two oxygen atoms then combine to form oxygen gas.

Complete Answer:
Green plants perform 'photosynthesis,' a physio-chemical process in which they use light energy to drive organic compound synthesis.

- There are two reasons why photosynthesis is important: it is the primary source of all food on earth. It is also responsible for the green plants releasing oxygen into the atmosphere.
- Photosynthesis happens as water and carbon dioxide are absorbed by the plant. The water molecules disassemble after the water has been absorbed. Then they are converted into sugar and oxygen. The molecules of water break into two elements which are oxygen and hydrogen.
- The water is broken down into component atoms when the electrons are removed from the water molecules. The atoms of oxygen from two molecules of water combine to form diatomic oxygen \[\left( {{O}_{2}} \right)\].
- The hydrogen atoms that are single protons that are lacking their electrons help to create a gradient of protons within the area occupied by the thylakoid membrane.
- The diatomic oxygen is released, and to repeat the process the chlorophyll centre binds to new water molecules. Because of the reactions involved, the chlorophyll requires energizing four electrons to produce one single oxygen molecule.

\[2{{H}_{2}}O\text{ }\to \text{ }4{{H}^{+}}{{O}_{2}}+4{{e}^{-}}\]

Note: An electron is removed from a molecule of water releasing the atoms of oxygen and hydrogen during the light reactions. The free oxygen atom joins with another free oxygen atom to create oxygen gas that is then released.