Deekchya Pandit

It is also a pathway for fixation and reduction of carbondioxide. It was discovered by Hatch and Slack in 1977. The first acceptor of CO₂is phosphoenol pyruvic acid and the first stable compound is oxalo acetic acid which is 4-carbon compound. So, this cycle is called C4 cycle. The anatomy of leaf of C4 plants is called krantz anatomy.

It is completed in the following ways:-

1. Fixation of CO takes place in mesophyll cell. In mesophyll cell, the affinity of PEP carboxylase (Phosphoenol pyruvic...

The major role of light during photosynthesis is toprovides energy for the synthesis of glucose from carbon dioxide and water. During light reaction, the chlorophyll entraps light and the solar energy is converted into chemical energy in the form of ATP molecules.

Differences between C3 cycle and C4 cycle are as follows:-

The utilization of oxygen and release of carbondioxide in presence of light during high temperature and low concentration of CO₂is called photorespiration.

It proceed in the following mechanism:-

1. During high temperature, high concentration of O₂and low concentration of CO₂, the affinity of Ribulose bi-phosphate (RuBP) carboxylase for CO decreases and for O increases and form oxyɡenase which catalyse the oxidation of RuBP to form 3-PGA(3-phospgoglyceric acid) and 2-phosphoglycolate.

RuBP +O...

When during hot, arid days, stomata opens only a little, enough carbon dioxide is not taken, so rubisco takes up oxygen and uses it in the Calvin cycle instead of carbon dioxide, this process of light dependent uptake of carbon dioxide and release of oxygen is called photorespiration.

It is the reaction which occurs in the stroma of chloroplast in absence of light or in dark condition. In this ATP and NADPH₂produced during light reaction are utilized as source of energy. It is studied in the following steps:-

1. Assimilation of carbondioxide or carboxylation:- It is the fixation of carbondioxide by RuBP in presence of RuBISCO enzyme. When RuBP reacts with carbondioxide, 6-carbon compound is formed which is unstable and converted into 3-carbin compound PGA phosphoglyceric...

Differences between cyclic and non-cyclic photophosphorylation are given below:-