What is the Difference Between Bacteriochlorophyll and Chlorophyll?

Bacteriochlorophyll and chlorophyll are both photosynthetic pigments that play a crucial role in the process of photosynthesis. However, they differ in their distribution, structure, and the type of photosynthesis they are involved in. Here are the key differences between bacteriochlorophyll and chlorophyll:

1. Distribution: Bacteriochlorophyll is found in phototrophic bacteria, such as purple bacteria, heliobacteria, and green sulfur bacteria. In contrast, chlorophyll is found in oxygenic phototrophs, including plants, algae, and cyanobacteria.
2. Types: There are four types of chlorophyll, with chlorophyll a and b being the most common. On the other hand, there are seven known variants of bacteriochlorophyll.
3. Structure: Both pigments have a distinctive tetrapyrrole ring with an Mg2+ in the center and a long 20-carbon chain. However, the differences occur in the substitutions around the ring and in the length and substitutions on the chain.
4. Photosynthesis Type: Oxygenic phototrophs, which contain chlorophyll, perform oxygenic photosynthesis, while anoxygenic phototrophs, which contain bacteriochlorophyll, perform anoxygenic photosynthesis.
5. Light Absorption: Chlorophyll a absorbs red light (around 680 nm) and is the main pigment in higher plants, many algae, and cyanobacteria. Bacteriochlorophyll a and b absorb infrared light, which allows them to utilize wavelengths of light not absorbed by plants or cyanobacteria.

In summary, bacteriochlorophyll and chlorophyll are both photosynthetic pigments with similar overall structures but different distributions, types, and light absorption capabilities. They are involved in different types of photosynthesis and are found in distinct groups of organisms.

Comparative Table: Bacteriochlorophyll vs Chlorophyll

Here is a table comparing the differences between bacteriochlorophyll and chlorophyll:

Bacteriochlorophylls and chlorophylls are both types of photosynthetic pigments found in different groups of phototrophic organisms. Bacteriochlorophylls are found in anoxygenic phototrophs such as purple heliobacteria and green sulfur bacteria, while chlorophylls are found in oxygenic phototrophs such as plants, algae, and cyanobacteria. There are seven types of bacteriochlorophylls and four types of chlorophylls. Both bacteriochlorophylls and chlorophylls absorb yellow and blue wavelengths from the electromagnetic radiation, which is why they appear green in color.