Question

Which one of the following is essential for the photolysis of water?
A. Manganese
B. Zinc
C. Copper
D. Boron

Answer 1

Photolysis of water refers to the splitting up of water in the presence of light. Photolysis of water requires the energy of light, an electron carrier, and oxygen-evolving complex or OEC.

Complete step by step answer: Photolysis is made up of two words, Photo meaning light and Lysis means the breaking. Thus, the photolysis of water is the breaking of the water molecules with the help of light. It can also be referred to as the breaking up of water into oxygen and hydrogen atoms by the illuminated chloroplast.
Let us look at all the options that are given to us one by one.
-Manganese: It is present in the oxygen-evolving complex. It helps in the photolysis of water during the light reaction in photosynthesis. The energy of the light brings about some changes in the Manganese. These changes help the manganese to remove an electron from the OH part of the water, leading to the formation of oxygen. It is an essential cofactor.
-Zinc: It is an important micronutrient in plants. It acts as a cofactor for many enzymes. It is an important component of the proteins and some macromolecules. It plays an important role in gene expression also.
-Copper: Copper plays a very important role in the metabolism of plants. It helps in the photosynthetic and respiratory ETS chains. It also helps in the sensing of ethylene, in the cell wall metabolism, and the biogenesis of the Molybdenum cofactor.
-Boron: Boron helps in the formation of the cell wall in the plants. It also helps in the maintenance of the functional and structural stability and integrity of the biological membranes. It helps in the movement of sugar into various plant parts along with the energy. Lastly, it facilitates pollination.
Thus, based on the above information we can conclude that Manganese is essential for the photolysis of water.
Hence, the correct answer is option (A).

Note: Photolysis is essential for photosynthesis. This is because the water is an essential source for hydrogen, protons, and electrons, and hydrolysis helps in releasing these. During photolysis two molecules of water, break to form four protons and four electrons. The protons contribute to the formation of the NADPH later on and the four electrons help in the formation of the ATP.