Question

What are phycobilins pigments?

Answer 1

Hint: Algae are the chlorophyll-containing photosynthetic organisms. They lack true roots, stems, leaves like any other vascular plant. Some of them are unicellular while most of them are multicellular. They form a symbiotic association with other organisms, like lichen, which is the symbiotic association between fungi and green algae.

Complete answer:
Phycobilins are light-harvesting pigments found in cyanobacteria, but they are not present in higher plants. Algae are chlorophyll-containing photosynthetic organisms. They lack true roots, stems, leaves like any other vascular plant. Some of them are aquatic while most of them are terrestrial and are mainly found in moist rocks, soil and trees. They may also live in colonies.

Light capturing pigments found in blue-green algae, in the chloroplast of red algae are called phycobilins. The water-soluble proteins are known as phycobiliprotein. Most of them also have chromophores which impart colour to them. They absorb the light and pass it to chlorophyll for the process of photosynthesis.

They absorb red, orange, yellow and green light wavelengths for the process of photosynthesis. There are three types of phycobilins:
- Phycoerythrobilin which is red in colour,
- Phycourobilin which is orange in colour,
- Phycocyanobilin which is blue in colour.

Note:
- The primary function of phycobilins is to supplement the light-capturing ability of Chl by absorbing energy where Chl is not a very efficient absorber.
- Phycobilins are water-soluble. The pigments are of two types— blue and red. The pigments are useful in chromatic adaptations.