Which micronutrient is required for splitting of water molecule during photosynthesis?
The micronutrient required for splitting water molecules during photosynthesis is manganese (Mn). Manganese is an essential cofactor for the water-splitting complex of photosystem II (PSII), which is one of the two photosystems involved in the light-dependent reactions of photosynthesis.
In the process of photosynthesis, light energy is absorbed by chlorophyll molecules in the thylakoid membranes of chloroplasts. This energy is used to drive a series of reactions, including the oxidation of water molecules into oxygen, protons (H⁺ ions), and electrons (e⁻). This water-splitting reaction occurs within the oxygen-evolving complex (OEC) of PSII, which contains manganese ions.
The manganese ions within the OEC undergo a cyclic process of oxidation and reduction, facilitated by the absorption of light energy. This process enables the water-splitting reaction, leading to the release of oxygen as a byproduct, which is essential for aerobic respiration and for sustaining life on Earth.
In addition to manganese, other essential nutrients, such as calcium (Ca), chloride (Cl⁻), and possibly other transition metals, also contribute to the structure and function of the water-splitting complex in photosystem II. However, manganese is particularly crucial for its role in facilitating the oxidation of water molecules and the release of oxygen during the light-dependent reactions of photosynthesis.