Question

What is the advantage of having more than one pigment molecule in a photocentre ?

Answer 1

A chromatographic separation of the leaf pigment shows that the colour that we see in leaves is not due to a single pigment but due to four pigments. Chlorophyll a bright or blue green in the chromatogram. Chlorophyll b which is yellow green. Xanthophylls which are yellow. Carotenoids which are from yellow to yellow orange in colour.

Complete Answer:
- Pigments are the substance that have an ability to absorb light at specific wavelengths.
- Chlorophyll a is the most abundant plant pigment in the world. Chlorophyll A is a pigment which absorbs light of different wavelengths.
- The maximum absorption of chlorophyll a that means in the blue and the red region also shows the higher rate of photosynthesis.By this we can conclude that chlorophyll a is the chief pigment associated with photosynthesis.
- Most of the photosynthesis takes place in the blue and red region of the spectrum some photosynthesis does take place at the other wavelengths of the visible spectrum.
- Though chlorophyll is the major pigment responsible for trapping light other pigments which are called accessory pigments also absorb light and transfer the chemical energy to chlorophyll a.
- Due to the accessory pigments more sunlight is also captured. And photo oxidation of chlorophyll is prevented.

Some additional information:
- The two types of reaction occur in photosynthesis.
- Light reaction which occurs in the presence of light.
- Dark reaction which occurs by the product formed in the light reaction.

Note: Light reaction takes place in grana and dark reaction take place in stroma. Both sites are present in the chlorophyll.