The different types of chlorophyll, in addition to ensuring the green color of plants, help in the process of photosynthesis.
Chlorophyll is the pigment that gives green color to some plant tissues, especially leaf tissues, and helps in the process of obtaining organic compounds (photosynthesis). The name of this pigment was proposed in 1818 by Pelletier and Caventou to designate a green substance that came out of the leaves when this organ was placed in alcohol.
Chlorophyll molecules, which are located inside chloroplasts in higher plants, are made up of complexes derived from a compound called porphyrin. They are unstable compounds and sensitive to light, heat, oxygen and some chemical processes. There are different types of chlorophyll, which are called a, b, c and d, and they differ by the structure of their molecule and their absorption capacity.
Chlorophyll a is the most abundant type, accounting for about 75% of all green pigments found in plants. It is found in virtually all organisms that perform photosynthesis, with the exception of some photosynthetic bacteria that have specialized pigments. It plays a fundamental role in the process of photosynthesis, actively acting in the production of organic substances.
Chlorophyll a is found in all photosynthetic eukaryotic organisms
Chlorophylls b, c and d act as accessory pigments in photosynthesis, helping to broaden the range of light that can be used in this process, complementing light capture. In addition to these chlorophylls, carotenoids and phycobilins are also considered accessory pigments. It is important to note that chlorophylls b, c and d cannot replace chlorophyll a in the photosynthesis process, acting exclusively as accessory pigments.
Chlorophyll b is found in plants, green algae and euglenophytes. The concentration of this type of chlorophyll is higher in shaded plants, as it increases the wavelengths that can be captured by the plant. Chlorophyll b can be converted to a by the action of the enzyme chlorophyll a oxygenase. In nature, chlorophylls a and b are found in a ratio of 3:1.
Chlorophyll c, in turn, has the same function as chlorophyll b and is a substituent of this in some groups of algae, such as diatoms and brown algae. Chlorophyll d is found in red algae.
Curiosity: Chlorophylls are used as natural dyes and antioxidants, which leads to the production of healthier foods.