Chlorophyll Structure - Definition, Types, Biosynthesis, Uses

Definition Of Chlorophyll

Chlorophyll is a green pigment in plants, algae, and cyanobacteria that accounts for their green colour. It is very essential to photosynthesis, the process by which light energy is converted into the form of chemical energy stored as glucose.

Chlorophyll mainly absorbs light from the blue and red parts of the spectrum but reflects green light; thus, giving off its green color in plants. This pigment has a significant role in capturing light energy and then transferring it to its energy converters within the plant cells, changing it into chemical energy that drives the synthesis of the organic molecules sustaining the growth of plants and ultimately supporting the food chain.

Structure Of Chlorophyll

Chlorophylls are complicated molecules, but basically, the structure includes mainly a porphyrin ring with a long hydrophobic phytol tail.

Porphyrin ring and its components

In the molecular structure of chlorophyll, there exists a porphyrin ring that includes four nitrogen-containing pyrrole rings, which act as light absorbers. This phytol tail will help anchor the chlorophyll molecule within the lipid membranes of the chloroplasts and more precisely in the thylakoid membranes where photosynthesis occurs.

Central magnesium ion.

This includes a magnesium ion at the centre of the ring for capturing light energy

Types Of Chlorophyll

The different types of chlorophyll are:

Chlorophyll a:

It is considered the most important pigment in photosynthesis due to the effective forms that enable it to absorb light energy from the blue-violet and red portions of the electromagnetic spectrum. This pigment participates in the light-dependent reactions of photosynthesis and it is responsible for converting light energy into chemical energy.

Chlorophyll b:

This is a light-harvesting or accessory pigment that broadens the ability of the plant to capture light energy by absorbing blue and red-orange light. It transfers the acquired light energy into chlorophyll and hence enhances the efficiency of photosynthesis.

Chlorophyll c and d:

Types of chlorophyll are found in some algae like brown algae diatoms, and red algae. Modified structures enable them to absorb light at different wavelengths. As such photosynthesis occurs in these sea algae in the various water environments where the conditions are unlike those on land.

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