Light-dependent electron flow with the production of ATP can occur without the formation of NADPH. This process is called ____, which involves only one of the photosystems, ____.
A) noncyclic photophosphorylation; P700
B) cyclic photophosphorylation; P700
C) noncyclic photophosphorylation; photosystem II
D) noncyclic photophosphorylation; P680
E) cyclic photophosphorylation; P680

Question

Quizplus · Accepted Answer

Cyclic photophosphorylation involves only photosystem I (P700) and can produce ATP without producing NADPH. Noncyclic photophosphorylation involves both photosystem I and II and produces both ATP and NADPH. Option A is incorrect because noncyclic photophosphorylation involves both photosystems. Option C is incorrect because although it involves only one photosystem (photosystem II), it still produces NADPH. Option D is incorrect because P680 is associated with photosystem II and not involved in cyclic photophosphorylation. Option E is incorrect because although it involves photosystem II, it is noncyclic and produces both ATP and NADPH.

Light-Dependent Electron Flow with the Production of ATP Can Occur