Plants are capable of producing their own food. The quintessential element that helps plants to absorb light which is then converted to glucose is called chlorophyll.
Chlorophyll is a coinage of two Greek words, ‘chloros’ and ‘phyllon’. ‘Chloros’ means green and ‘phyllon’ means leaf. Chlorophyll is the green pigment found in plants and algae. It is a biomolecule that plays the most vital role in photosynthesis. Chlorophyll present in green leaves allow the plant to absorb sunlight which is the source of its energy. Due to its color, chlorophyll is a ready absorber of blue and red light in the electromagnetic spectrum. It doesn’t absorb much green or colors close to the green spectrum. Conversely, that is the reason why chlorophyll appears to be green. Leaves also get their green color because of the chlorophyll content.
Chlorophyll: The Biomolecule
First identified by Pierre Joseph Pelletier and Joseph Bienaimé Caventou in 1817, chlorophyll is chemically referred to as a chlorin pigment. The chemical or molecular formula of chlorophyll was not discovered until almost a hundred years after Caventou and Pelletier succeeded with the isolation of the pigment. Over the last century, the molecular formulas of chlorophyll have been figured out. They are C55H72O5N4Mg, C55H70O6N4Mg, C35H30O5N4Mg, C35H28O5N4Mg, C54H70O6N4Mg and C55H70O6N4Mg. The various types of molecular structures found in the pigment are classified into the C2 group, C3 group, C7 group, C8 group and C17 group.
Role of Chlorophyll in Photosynthesis
There are two main functions of chlorophyll. The first function of the innumerable molecules present in the pigment is to absorb light and to transfer the light energy to the reaction center in the photosystem of a plant which has a particular chlorophyll pair. There are two photosystems in plants, referred to as photosystem I and photosystem II. Each has its own reaction center. The reaction centers are called P680 and P700. Both reaction centers convert the energy from the photons, ala light, and transfer the energy to an electron.
This process is known as charge separation and is done entirely in the reaction centers. Subsequently, the plant uses carbon dioxide and water combined with the chlorophyll and absorbed light energy to make food, ala glucose. In the process, plants also produce oxygen which is the primary source of all oxygen in the atmosphere.
Chlorophyll is not only a life source for plants but by default also for animals whose primary or only source of food is plants.