Question

What is a pigment? Give an example.

Answer 1

Hint: Pigments are usually those substances that provide colour to the cells and tissues in an organism. Moreover, the green color of the plants is due to chlorophyll and the red color of the blood is due to haemoglobin, both of which are pigments.

Complete step by step answer: Pigments are those substances that give cells and tissues their colors. It is either partially or completely insoluble in water. Also, pigments are inorganic substances. Apart from imparting color to the cells, sometimes pigments perform some special functions also.
-Some examples of common types of pigments found in the plants are –
Chlorophyll is the main photosynthetic pigment found in plants. It imparts the green color to leaves. Other than that, it helps in photosynthesis, as it participates directly in the light reaction. Chlorophyll is of five types. These five types are chlorophyll a, chlorophyll b, chlorophyll c, chlorophyll d, chlorophyll e. Amongst these the chlorophyll a is known as the universal pigment. Carotenoids are the secondary pigments found in plants. They are carotene pigments (orange or red-colored), or xanthophyll pigments (yellow colored). Phycobilins are hot water-soluble pigments. They are present in cyanobacteria and red algae. They are either phycocyanin (blue colored) or phycoerythrin (red-colored).
-Some examples of common types of pigments found in the animals are –
Haemoglobin is the main respiratory pigment present in our body. It helps in the exchange of respiratory gases and the transportation of oxygen to all parts of the body. The skin has a melanin pigment that is responsible for giving color to the skin. Besides, it protects the skin from harmful UV rays.

Note: The structure of the chlorophyll molecule is said to be tadpole-like, with a head and a tail. The head is a porphyrin head that is made up of four tetrapyrrole rings with magnesium in the center. The tail is the phytol tail. The structure of hemoglobin is similar to the head of the chlorophyll except that in the hemoglobin molecule the iron atom replaces magnesium.