What are Pigments?
Pigments are defined as the set of compounds that have an intense colour and are used in the colouring of other materials. These colouring substances are also called Biological Pigments or the Biochromes, which mainly refers to the true pigments. These biological pigments are insoluble in water and are applied as ground particles in solid form with the liquids. We can find various type of Biological pigments in both plants as well as animals.
The pigments are produced by the living organisms and have a colour, which results from the colour absorption techniques. There are two different types of pigments an are classified base on their sources.
The organic pigments are made from some of the natural sources.
The inorganic pigments, also called the synthetic pigments are derived from the coal tars and some of the other form of petrochemicals. In some rare cases, these pigments can also be synthesized by a simpler form of chemical reactions called oxidation.
Pigments are the chemical substances, which exhibit wavelengths of the visible light, making them appear colourful. Plants, flowers, algae, certain photosynthetic bacteria and even the skin of animals have a particular type of pigments, which provide colours and also have an ability to absorb some wavelengths.
Types of Pigment in Plants
Plants have a unique feature of capturing the light energy and convert it into sugars through the process called photosynthesis. The process begins with the absorption of light energy by some specialized form of organic molecules, called the pigments. The photosynthesis, a biological process requires green coloured pigment called chlorophyll along with other forms of yellow and red coloured pigments.
Other essential plant pigments include anthocyanins, betalains, carotenoids, porphyrins and much more. All these pigments stimulate the process of chemical reactions by reflecting the wavelengths.
The essential types of plant pigments are discussed below-
Chlorophyll is one of the primary pigment found within the plant cells of all green plants. The green colouring of the plant leaves and the tender part of the stem is due to the presence of a pigment called chlorophyll. The chlorophyll pigment is the most significant and essential pigments, as it plays a vital role in the biological process of photosynthesis.
There are different types of chlorophyll pigments and are classified mainly based on their structure, functions and other features. The different types of chlorophyll pigments are:
Chlorophyll a– found in algae, cyanobacteria and in all higher plants.
Chlorophyll b– found only in green algae and in higher plants.
Chlorophyll c– found in certain photosynthetic Chromista and in some marine algae.
Chlorophyll d– found only in red algae.
Chlorophyll e– found only in algae.
Among all these five types of chlorophyll pigments, chlorophyll a and b are considered as the primary photosynthetic pigments.
Carotenoids are the pigments in the form of orange, red, yellow colours. These compounds are insoluble in water and are attached to the membranes of the cell bodies. These Biomolecules are antioxidants which promote a good eyesight in humans.
Anthocyanins are a type of flavonoid pigments found naturally in all the tissues of the higher group of plants. This pigment functions by providing colour to the stem, leaves, roots, fruits, and flowers. Based on their pH, these type of pigments appears red, blue, purple and other dark colours.
Flavonoids are a type of yellow coloured pigments, which are abundantly found in lemons, grapefruit, oranges and in some ark and yellow coloured flowers. This type of pigments is largely found in the plastids and cytoplasm of the plant cell. Flavonoids are the chemicals with the antioxidant properties and help in lowering the cholesterol levels.
Other applications of flavonoids are:
They are extracted and utilized as dyes.
These pigments such as lycopene and astaxanthin are used as a dietary supplement in most of the food products.
For more information about the pigments, its types, functions and other related topics, visit us at BYJU’S Biology.