What is the definition of non-cyclic photophosphorylation?

Non-cyclic photophosphorylation is defined as a process where both ATP and NADPH are produced through the conversion of light energy, utilizing water (H2O) as an electron donor, which results in the release of oxygen (O2). In this process, the light reactions of photosynthesis occur in the thylakoid membranes of chloroplasts.

During non-cyclic photophosphorylation, light energy is absorbed by chlorophyll, causing the water molecules to split in a process known as photolysis. This not only provides electrons but also releases oxygen as a byproduct. The energized electrons move through the electron transport chain, facilitating the conversion of ADP and inorganic phosphate into ATP, as well as reducing NADP+ to NADPH. Both ATP and NADPH are then used in the Calvin cycle, which takes place during the light-independent reactions of photosynthesis.

This process is distinct because it directly relies on light and occurs continuously during the day when light is available, contrasting with nocturnal processes that occur in the absence of light or methods that rely on stored energy.