ATP is generated in this one-way flow of electrons using an electron transport chain to drive phosphorylation in the light reactions. Hence the name photophosphorylation. NADPH and ATP are both used in the fixation of CO2 into monosaccharides in the Calvin cycle.This is called cyclic photophosphorylation.

Explanation:

ATP production in photosynthesis:
Photosynthesis is the process by which green plants, algae, and some bacteria convert light energy into chemical energy in the form of glucose. ATP (adenosine triphosphate) is the energy currency of cells and is produced during the light-dependent reactions of photosynthesis. The production of ATP in photosynthesis is called photophosphorylation.

Light-dependent reactions:
The light-dependent reactions occur in the thylakoid membrane of the chloroplasts and involve the absorption of light energy by chlorophyll molecules. These reactions produce ATP and NADPH, which are used in the light-independent reactions (Calvin cycle) to synthesize glucose.

Photophosphorylation:
Photophosphorylation is the process of generating ATP using light energy. It occurs in two forms:

1. Non-cyclic photophosphorylation:
In non-cyclic photophosphorylation, light energy is absorbed by chlorophyll molecules in photosystem II (PSII), which excites electrons. These excited electrons are then passed through a series of electron carriers, resulting in the generation of ATP through chemiosmosis. The electrons lost by PSII are replaced by splitting water molecules, releasing oxygen as a byproduct.

2. Cyclic photophosphorylation:
In cyclic photophosphorylation, light energy is absorbed by chlorophyll molecules in photosystem I (PSI), which excites electrons. These excited electrons are then passed through a series of electron carriers and ultimately return to PSI. This cyclic electron flow generates ATP through chemiosmosis but does not produce NADPH or release oxygen.

Conclusion:
The ATP production in photosynthesis is called photophosphorylation, as it involves the phosphorylation of ADP (adenosine diphosphate) to ATP using light energy. This process occurs during the light-dependent reactions of photosynthesis and can occur in both non-cyclic and cyclic forms. Photophosphorylation is essential for providing the energy necessary for the synthesis of glucose and other organic molecules in the light-independent reactions of photosynthesis.

Mitochondria and chloroplast synthesis ATP from ADP and inorganic phosphate with the help of light( or photons) that's why we named it photo - phosphorylation. Cyclic and non-cyclic depends on how many photosystems are working together.....