Chlorophyll A vs B
Chlorophyll A and Chlorophyll B are two types of chlorophyll. Chlorophyll is the substance that is present in the leaves of plants and is responsible for their green color as seen by us. Chlorophyll absorbs sunlight and makes use of this energy to synthesize carbohydrates from water and carbon dioxide. This process, called photosynthesis, is responsible for sustaining life processes in all plants as their energy requirements are met through this process. Now since both humans and animals eat plants as a source of food, photosynthesis is just as important for us too. The chemical equation that shows how plants use sunlight in the presence of chlorophyll to make food for them is as follows.
6CO2 + 6H2O → C6H12O6 + 6O2
C6H12O6 – Glucose
There are mainly two types of chlorophylls, A, and B. Both of them are photoreceptors in the sense that they can make use of sunlight to make food for plants. The only difference lies in the composition of their molecules where in the side chain of A, the molecule is CH3, while it is the CHO molecule in the side chain in chlorophyll B.
Both chlorophylls are present in plant leaves and tune their absorption of light at different wavelengths, so that light that chlorophyll A cannot absorb efficiently at 460nm is absorbed strongly by chlorophyll B. It is clear then that both A and B compliment each other in absorbing sunlight. All energy requirements of plants are fulfilled in the red and violet part of the spectrum in sunlight. However, there is a large part of this spectrum in the range of 500-600nm which is not absorbed by either of the chlorophylls. This light lies in the green spectrum, and since most of it is reflected back, we see plants as green.
When plants are cooked by human beings to be eaten as food, most of the chlorophyll is destroyed which explains why these leaves appear pale and yellow green when we boil them. In nature also, chlorophylls in plant leaves decay in autumn. This makes green leaves to change their color graduall and green fades into oranges and reds of carotenoids.
Chlorophyll is the molecule that works as photoreceptor in leaves of plants
Both chlorophyll A and Chlorophyll B work as photoreceptors and compliment each other by fulfilling the energy requirements of plants
The major difference between A and B is the molecule CH3 in the side chain in A, while it is CHO in B
Energy absorption at wavelengths at which A is ineffective is done by B and vice versa.