Question

Which is an essential component of chlorophyll?
a. Mn
b. Cu
c. Mg
d. Fe

Answer 1

Chlorophyll is a pigment that is present in all green plants and a few other organisms. It is required for photosynthesis, which is the process by which light energy is converted into chemical energy. Chlorophyll absorbs energy from sunlight, and this energy is later used to convert carbon dioxide into carbohydrates.

Complete answer:
Chlorophyll is an essential pigment required in photosynthesis, allowing plants to absorb energy from light. Chlorophylls mostly absorb light strongly in the blue portion of the electromagnetic spectrum as well as the red portion.

Manganese plays a minor role in maintaining the structure of the chloroplast.

Copper is required by the plants for photosynthesis in chloroplasts because it is a cofactor of plastocyanin, an essential electron carrier in the thylakoid lumen.

Magnesium is located centrally in the chlorophyll molecule and is structurally very important.

Iron takes part in electron transport during photosynthesis.

Hence, the correct answer is option (C).

Additional information:
Chlorophyll molecules are light trapping green pigments in plants. They are made up of a cyclic tetrapyrrole head and a long phytol tail attached to the head. One atom of magnesium is directly coordinated to the four pyrrole rings in the cyclic tetrapyrrole head. Thus, magnesium is an important structural component of chlorophyll molecules.

Iron is an essential micronutrient for plants. It is required for the synthesis of chlorophyll and has several other functions also. Plants also require exposure to light to synthesize chlorophyll. In absence of light, plants will be thin and pale. Such plants are called etiolated plants.

Note: Magnesium is centrally located in the chlorophyll. It consists of a porphyrin ring which has magnesium ions in the center. The two types of chlorophyll are chlorophyll a and b. Chlorophyll a has a porphyrin ring with the side chain of the methyl group and a phytol chain. Chlorophyll b has a porphyrin ring with the side chain of the aldehyde group and a phytol chain. It acts as an accessory pigment.