photophosphorylation

(fō'tō-fŏs'fôr-ə-lā'shən, -fər-)
n.
Phosphorylation induced by radiant energy in photosynthesis.

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or photosynthetic photophosphorylation

the metabolic processes by which photosynthetic organisms use light energy to convert ADP to ATP without the concomitant reduction of dioxygen to water that occurs in oxidative phosphorylation (see photosynthesis). There are two distinct electron transport mechanisms: in noncyclic photophosphorylation, which involves both photosystems I and II, ATP synthesis is linked to the transport of electrons from water to NADP⁺, with production of NADPH and dioxygen; in cyclic photophosphorylation, which involves only photosystem I, ATP synthesis is driven by a proton gradient generated across the thylakoid membrane.

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