Chlorophyll A vs B
Plants and algae are living organisms that can create their own food and animals get their food from these plants. This food creating process is called photosynthesis and uses chlorophyll.
Chlorophyll is a green pigment in plants and algae which is essentially used in photosynthesis. It absorbs light and energy from the blue and red portions of the electromagnetic spectrum but does not absorb the green portion well which gives chlorophyll containing tissues in plants their green color
The light and energy are then transferred to the reaction centers of two photosystems, Photosystem I and Photosystem II. These photosystems have reaction centers, P680 and P700 which absorb and use the energy they receive from other chlorophyll pigments. Photosynthesis uses two types of chlorophyll, chlorophyll a and b, to produce energy.
Chlorophyll A
Chlorophyll a absorbs energy from wavelengths of blue-violet and orange-red light at 675 nm. It reflects green light which gives chlorophyll its green appearance. It is very important in the energy phase of photosynthesis because chlorophyll a molecules are needed before photosynthesis can proceed.
It is the primary photosynthetic pigment. It is the reaction center of the antenna array which is made up of core proteins that bind chlorophyll a with the carotenoids. Organisms, specifically oxygenic photosynthetic ones use chlorophyll a and it uses various enzymes for biosynthesis.
Chlorophyll B
Chlorophyll b absorbs energy from wavelengths of green light at 640 nm. It is the accessory pigment that collects energy and passes it on to chlorophyll a. It also regulates the size of antenna and is more absorbable than chlorophyll a.
Chlorophyll b complements chlorophyll a. Its addition to chlorophyll a increases the absorption spectrum by increasing the range of wavelengths and broadening the spectrum of light that is absorbed.
When there is little light available, plants produce more chlorophyll b than chlorophyll a to increase its photosynthetic ability. This is necessary because chlorophyll a molecules capture a limited wavelength so accessory pigments like chlorophyll b are needed to aid in the capture of a wider range of light.
It then transfers the captured light from one pigment to another until they reach the chlorophyll a in the reaction center. Chlorophyll a cannot function well without the help of chlorophyll b and chlorophyll b cannot effectively produce enough energy on its own.
These two types of chlorophylls are therefore both very essential in the process of photosynthesis. They work best together.
Summary
1. Chlorophyll a is the primary photosynthetic pigment while chlorophyll b is the accessory pigment that collects energy and passes it on to chlorophyll a.
2. Chlorophyll a absorbs energy from wavelengths of blue-violet and orange-red light while chlorophyll b absorbs energy from wavelengths of green light.
3. Chlorophyll a absorbs energy at 675nm while chlorophyll b absorbs energy at 640 nm.
4. Chlorophyll b is more absorbent while chlorophyll a is not.
5. Chlorophyll a is the reaction center of the antenna array of core proteins while chlorophyll b regulates the size of the antenna.