Plants are living creatures that depend on themselves for food. The process that they use for creating their food is known as photosynthesis. This process requires a pigment called chlorophyll.
Both of these play significant roles in the process of photosynthesis as they help to absorb sunlight that is needed for the production of carbohydrates.
Chlorophyll A vs B
The difference between chlorophyll A and chlorophyll B is regarding their part in photosynthesis. Chlorophyll A is the most important pigment used in the process of photosynthesis whereas chlorophyll B is the secondary pigment, as it collects the energy and passes it to chlorophyll A.
Comparison Table
| Parameters of Comparison | Chlorophyll A | Chlorophyll B |
|---|---|---|
| Definition | Chlorophyll A is the prime pigment used in photosynthesis. It captures sunlight. | Chlorophyll B is the additional pigment used in photosynthesis. It collects sunlight and passes it to chlorophyll A. |
| Range of absorption | 430 mm to 660 mm. | 450 mm to 650 mm. |
| Color of absorption | This absorbs orange-red and blue-violet light. | This absorbs orange-red light. |
| Reflecting color | Chlorophyll A reflects a blue-green color. | Chlorophyll B reflects a yellow-green color. |
| Absorbing wavelength | It absorbs wavelength 430 nm and 662 nm. | It absorbs wavelength 470 nm. |
| Structure | Chlorophyll A contains a methyl group. | Chlorophyll B contains an aldehyde group. |
| Molecular Weight | 839.51 g/mol | 907.49 g/mol. |
| Chemical Formula | C55H72MgN4O5 | C55H70MgN4O6 |
| Found in | It is found in algae, plants, and cyanobacteria. | It is found in algae and plants. |
| Quantity | ¾ of total chlorophyll. | ¼ of total chlorophyll. |
| Solubility in polar solvents | Low | High |
What is Chlorophyll A?
Chlorophyll A refers to the green pigment which helps in absorbing light and providing energy in the process of photosynthesis. It is present in algae, cyanobacteria, and all plants.
Chlorophyll A is regarded as the most essential pigment for plants as it plays an important role in photosynthesis. It helps in the electron transport chain during photosynthesis.
It is also responsible for transferring light energy from the antenna to the photosystems P680 and P700. Here chlorophylls are found in the thylakoid membrane of the chloroplast.
The wavelengths responsible for violet-blue and orange-red colors are 429 nm and 659 nm respectively.
It reflects bluegreen color, which brings out the green color in most plants.
Chlorophyll A has a chlorin ring. Here a magnesium ion is surrounded by four nitrogen atoms. It also consists of some side chains and hydrocarbon tails.
Hence, we can say that the basic role of Chlorophyll A is to absorb light from the orange-red and violet-blue colors of the spectrum and transfer this energy to the reaction center.
What is Chlorophyll B?
Chlorophyll B is a green pigment that helps in photosynthesis as it collects light energy and then passes it to chlorophyll A. It is present in plants and green algae.
The wavelengths responsible for violet and red colors are 455 nm and 642 nm respectively.
It reflects a yellow-green color. Chlorophyll B is present in light trapping antenna in photosystem P680 in most land plants.
Hence, we can say that the main role of Chlorophyll B is to increase the absorption spectrum of organisms. This helps them to absorb more energy and basically helps organisms to convert more energy from the sun into chemical energy.
Main Differences Between Chlorophyll A and B
- ¾ of the total chlorophyll in plants constitute Chlorophyll A. ¼ of the total chlorophyll in plants constitute chlorophyll B.
- Chlorophyll A is there in the reaction center of the antenna array. Chlorophyll B controls the size of the antenna.
References
- https://www.sciencedirect.com/science/article/pii/S0034425798000467
- https://pubs.acs.org/doi/pdf/10.1021/ja00964a011
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