Before starting the difference between chlorophyll A and B, let have a look on chlorophyll. Chlorophyll is a green pigment. It is present in all photosynthetic organisms. It is insoluble in water but it is soluble in organic solvents like carbon tetra chloride (CCl4), alcohol etc. (Read More)
Difference between Chlorophyll a and b
- There is difference of only one functional group of porphyrin ring between chlorophyll a and chlorophyll b. Chlorophyll a has methyl group (CH3) and chlorophyll b has carbonyl group (CHO) in place of methyl group. The molecular formula of the chlorophyll a and b are:
- Chlorophyll a: C55H72O5N4Mg
- Chlorophyll b: C55H70O6N4Mg
- The two chlorophylls show slightly different absorption spectra. So, these chlorophylls have different colors. Some waves that are not absorbed by chlorophyll a are absorbed by the chlorophyll b and vice versa. The difference in structure of different pigments increases the range of wave length of the absorbed light. Chlorophyll a is blue- green and chlorophyll b is yellow-green.
- Chlorophyll a is the most abundant and most important photosynthetic pigment. It takes part directly in the light reaction of the photosynthesis.
It converts solar energy in to chemical energy. It is present in all photosynthetic organisms but it is absent in the photosynthetic bacteria. Chlorophyll a has several forms. These forms differ slightly in their red absorbing peaks (limits).
For example, they may absorb wave length of red colour of 670, 680, 690, and 700 nm. Chlorophyll b is present with chlorophyll a in all green plants and green algae.