Chlorophyll Definition

Introduction

Pigments which are responsible for the green colour in plants are chlorophyll pigments. Chlorophyll is one that among the major groups of the pigment, which are responsible for the conversion of sunlight into chemical energy and all this process occurs in the photosynthesis process.  As the main function of chlorophyll is the absorption of sunlight, this energy is helpful in the conversion of carbon dioxide into carbohydrates. During all this process, oxygen is released as a by-product of photosynthesis. Along with plants, chlorophyll is also present in some organisms like Cyanobacteria. 

Chlorophyll is further divided into various forms like chlorophyll a, chlorophyll b, chlorophyll c, etc but among them, chlorophyll a and chlorophyll b are mainly present in higher plants and green algae. Whereas chlorophyll c is found in marine algae and chlorophyll d is found in some of the species of cyanobacteria. Chlorophyll e is very rare as it is hardly found in few algae, like golden algae. Apart from all these things, chlorophyll structure is almost similar to structure of haemoglobin. 


Location of Chlorophyll in Chloroplast:

Pigments of chlorophyll are mainly a green colour and they are light-dependent reactions. They absorb light from the sun i.e. red and blue light and convert this light into chemical energy which is their most important role in photosynthesis. In chloroplast, there is a structure termed as grana, which is made up of stacks of flattened discs called thylakoids and these thylakoids contain the photosystem and in these photosystems, photosynthetic pigments are present. 


Role of Chlorophyll in Photosynthetic Process: 

The major role of chlorophyll is in photosynthesis, as during this process plants absorb light energy and this light energy is converted into chemical energy. Using sunlight, carbohydrate synthesis takes place with the help of carbon dioxide and water. We can see the presence of chlorophyll in almost all green plants and some organisms like: green plants, cyanobacteria, and algae. In the photosynthesis process, chlorophyll absorbs sunlight of different wavelengths and with the help of carbon dioxide and water, they perform the synthesis process of carbohydrates. In chlorophyll, a magnesium ion is present in abundant amounts and this forms a large ring-like structure known as chlorine. A characteristic feature of chlorine rings is that they are heterocyclic compounds derived from pyrrole.


Important Features of Chlorophyll:

Some of the features of chlorophyll are discussed below:

A. Chlorophyll are known to be  fat-soluble organic molecules having tetrapyrrole ring and due to this reason they are called the “Tetrapyrrole pigments or Magnesium chlorine”. 

B. They are known to be food producers of the cell found in green plants, and they are mainly located in the chloroplast

C. Chlorophyll works as a factor for the proper growth of healthy and green plants. 

D. Chlorophyll is also present in the mesophyll cells in the leaves of green plants. 

E. Chlorophyll has a tendency to reflect green colour by absorbing red and blue wavelengths of light from sun rays. 

F. It is also known as power of the cell-like mitochondria, as they help in the production of ATP. 

G. Chlorophyll structure is similar to that of heme group of haemoglobin and cytochromes, which is derived from protoporphyrin

Difference Between Chlorophyll a and Chlorophyll b:

Chlorophyll a 

Chlorophyll b

It is considered a major photosynthetic pigment. 

It is considered as an accessory photosynthetic pigment. 

Mainly present in all plants, algae, bacteria, cyanobacteria and phototrophs.

Mostly present in green algae and in the plants.

They mainly absorb violet-blue and orange-red light from the spectrum.

They mainly absorb orange-red light. 

They are mainly blue-green.

They are mainly yellow-green in color. 

They are mainly soluble in petroleum ether

They are mainly soluble in methyl alcohol. 


Difference Between Chlorophyll and Chloroplast:

Chlorophyll 

Chloroplast

They give green color to plants. 

It is an organelle where photosynthesis occurs. 

There are mainly five types of chlorophyll: a, b, c, d, f

There are no further subtypes of the chloroplast. 

In chlorophyll, carotenoids have yellow and red pigments, green pigment

They have no pigments. 

This pigment carries out photosynthesis. 

This organelle carries out photosynthesis.

They are present in chloroplast. 

They are present in plant cells. 

They are present inside chloroplast, in thylakoid membranes

They are present throughout the plant cells, especially leafy parts. 

They don't have their own DNA.

They have their own DNA, present in them. 

FAQs (Frequently Asked Questions)

1. Define The Term Chlorophyll?

Ans. Green colour which is present mainly in plants and few other organisms like bacteria, algae is because of the presence of the chlorophyll pigment. This pigment is required during photosynthesis as it helps in conversion of light energy into chemical energy.  


2. Why Do Darker Leaves Have More Chlorophyll?

Ans. Plants which grow in shady areas or areas where the intensity of light is lower than in that area mainly have chlorophyll b, as it can absorb low intensity sunlight. Due to this reason leaves of such plants are in darker color in comparison to plants which are grown in high light intensity areas.