Biological pigments

Biological Pigments

Biological pigments, also known as biochromes, are substances produced by living organisms that have a color resulting from selective color absorption. These pigments are crucial for various biological functions, including photosynthesis, camouflage, and signaling.

Types of Biological Pigments

Biological pigments can be classified into several types based on their chemical structure and function:

1. Chlorophylls

Chlorophylls are green pigments found in the chloroplasts of plants, algae, and cyanobacteria. They play a vital role in photosynthesis by absorbing light energy, primarily in the blue and red wavelengths, and converting it into chemical energy.

2. Carotenoids

Carotenoids are yellow, orange, or red pigments found in plants, algae, and photosynthetic bacteria. They are important for photosynthesis and also provide photoprotection by dissipating excess light energy. Carotenoids include compounds such as beta-carotene, lutein, and zeaxanthin.

3. Anthocyanins

Anthocyanins are water-soluble pigments that appear red, purple, or blue depending on the pH. They are found in the vacuoles of plant cells and are responsible for the colors of many fruits, flowers, and leaves. Anthocyanins also have antioxidant properties.

4. Melanins

Melanins are dark pigments found in the skin, hair, and eyes of animals. They provide protection against ultraviolet radiation and contribute to the coloration of skin and fur. Melanins are also found in some fungi and bacteria.

5. Bilirubin and Biliverdin

Bilirubin and biliverdin are pigments derived from the breakdown of heme in red blood cells. Bilirubin is yellow, while biliverdin is green. These pigments are involved in the coloration of bruises and the yellowing of the skin in jaundice.

Functions of Biological Pigments

Biological pigments serve various functions in organisms:

• Photosynthesis: Pigments like chlorophylls and carotenoids are essential for capturing light energy in photosynthetic organisms.
• Protection: Pigments such as melanins protect against UV radiation and oxidative damage.
• Camouflage and Signaling: Pigments can provide camouflage or serve as signals for mating and warning in animals.
• Antioxidant Activity: Some pigments, like anthocyanins, have antioxidant properties that protect cells from damage.

Also see

• Photosynthesis
• Chlorophyll
• Carotenoid
• Melanin
• Anthocyanin