Question

How does photosynthesis use oxidation and reduction?

Answer 1

Hint: Oxidation is the type of chemical reaction where the addition of oxygen or loss of electrons occurs on a substance. The opposite reaction to oxidation is called reduction, where the addition of hydrogen or gain of electrons occurs on a substance.

Complete answer:
Photosynthesis is a chemical process used by green plants and few other organisms to convert light energy into chemical energy. The sugar produced by this process is converted into ATP. Sunlight functions as the main source of light energy, while carbon dioxide and water are the main reactants. In the presence of sunlight, carbon dioxide and water react to form sugar molecules.
In eukaryotic organisms, this occurs in the chloroplasts present in the mesophyll cells of the green leaves. The chlorophyll pigments absorb light energy.
In prokaryotic organisms like cyanobacteria, photosynthesis occurs in the foldings of the plasma membrane.

Photosynthesis is a redox mechanism where carbon dioxide is reduced to form sugar molecules, and water molecules are oxidized to form oxygen molecules. The molecular oxygen is released as a byproduct. The water molecules are split into hydrogen and oxygen molecules. The hydrogen molecules react with carbon dioxide and reduce them to form sugar molecules.

Both of these reactions occur simultaneously.

A molecule, atom, or ion undergoes oxidation when either of these conditions is satisfied- the addition of oxygen or removal of hydrogen or loss of electrons or increase in the oxidation state. The species oxidizing them is called the- oxidizing agent, and it itself undergoes reduction.

In the process of photosynthesis, the water undergoes oxidation to give oxygen molecules. The water molecule splits into an electron, oxygen, and hydrogen atoms in the presence of sunlight. The electrons are released from the oxygen in the water molecule. These electrons are then energized and accepted by the electron acceptor- PS II or photosystem II. The NADP+ molecule accepts electrons and hydrogen from the splitting of the water molecules- and undergoes reduction to form an NADPH molecule.

A molecule, atom, or ion undergoes reduction when either of these conditions is satisfied- the addition of hydrogen or removal of oxygen or gain of electrons or decrease in the oxidation state. The species reducing them is called the- reducing agent, and it itself undergoes oxidation.
In the process of photosynthesis, the carbon dioxide undergoes reduction to give sugar molecules. The NADPH molecule formed during the oxidation of water gives away its electrons and releases protons and NADP+. These electrons and hydrogen atoms are used for the reduction of carbon dioxide. The electrons reduce carbon dioxide to form sugar molecules or glucose. The oxidation state of carbon decreases in this process.

Note: A redox reaction is also called an oxidation-reduction reaction and involves a transfer of electrons between more than two species. The oxidation and reduction reaction occurs simultaneously. One species undergoes oxidation while the other undergoes reduction. Photosynthesis is a type of redox reaction.