Photosynthesis

Photosynthesis

Photosynthesis is a process, in which plants manufacture their food in the presence of chlorophyll and sunlight by the combination of carbon dioxide and water to form simple Carbohydrates.

In this process, Oxygen is released. it is important to note that the amount of Carbon dioxide (CO2) consumed in this process the equal to the amount of Oxygen is released. 

In Photosynthesis not only simple carbohydrate is formed, but also a considerable amount of energy which is initially obtained from sunlight as a Radiant Energy. This energy is transferred by green cells into chemical energy.

The Process of Photosynthesis can also be shown by the following equation.

Photosynthesis is oxidation, and reduction process, in which water is oxidized and carbon -dioxide is reduced to carbohydrates. the water and oxygen are produced as by-products.

In terms of energy, Photosynthesis can be defined as; The Metabolic process during which light energy is converted into Chemical energy or Food energy in the presence of chlorophyll and electron carriers.

Photosynthesis can also be defined as the formation of carbon-containing food compounds form carbon- dioxide and water, in green cells of the plant by the use of light energy. 

In Photosynthesis not only simple carbohydrates are formed, but also a considerable amount of energy which is initially obtained from sunlight as Radiant energy is transferred by green cells into Chemical energy.

Role of Chlorophyll and Other Pigments in Photosynthesis

The Chloroplasts are the chlorophyll-containing organelles. Each photosynthetic cell of the leaf has about 20 to 100 chloroplasts are present. 

Each chloroplast consists of three parts  

1.  Surrounding double membrane
2.  A liquid called Stroma that is surrounding by the double membrane.  It has important enzymes required for the formation of carbohydrates. 
3. Thylakoids: These are sets of flattened sac-like structures, which are embedded in the stroma. The thylakoid membrane contains inter fluid-filled cavity or lumen. This Cavity (lumen) is separated from stroma by Thylakoid membrane. The columns of thylakoid are called Granna

• Chlorophyll and other Photosynthetic  Pigments are present in the Thylakoid – Membranes, and show the green colour of the plant. 
• Electron acceptors of Photosynthesis are also present in the Thylakoid membranes, so Thylakoid membranes are involved in the formation of ATP Compounds.

Chlorophyll and other pigments absorb sunlight. This light energy is converted into chemical energy of ATP, and NADPH.

The ATP and NADH, are used to prepare glucose in, Phaelophytin (Gray), Xanthophylls (yellow), Chlorophyll-a (blue-green ), and Chlorophyll-b (yellow-green) Pigments.

Chlorophylls are of different types A, B, C, D.

The formula of chlorophyll a and b is given below:                                                                                              

Photo System in Plants

• As you know the Photosynthesis takes place by the help of light energy, which is absorbed by photosynthetic pigments. 
• The photosynthetic pigments are found in the groups called photo-system. 
• The photosystem consists of two parts: Light-gathering part, called antenna complex, and a Reaction centre. 
• The antenna complex contains many molecules of chlorophyll –a   and chlorophyll – b, and carotenoid molecules.

When light energy is received by the plant, It transfers from one pigment molecule to another pigment molecule, until it is reached to the Reaction Centre where the chemical reaction of photosystem occurs, and light energy is converted into chemical energy.