Question

Distinguish between photoreduction and photophosphorylation.

Answer 1

Answer: Photoreduction: Reduction is the gain of electron and the photoreduction is the gain of the electron in the presence of light. For example, Iron (III) accept one electron (reduced) in the presence of light and converted into Fe (II). This type of reaction takes place in photosynthesis. In photosynthesis, the reaction centres of (PS-I and II) accept one or more electron in the presence of light and induced into their transient state to transfer the electrons to the neighbouring electron carriers.

Photophosphorylation: The conversion of ADP into ATP in chlorophyll in the presence of sunlight in PS-I and PS-II. There are two types of photophosphorylation; Cyclic (in PS-I) and non-cyclic photophosphorylation (PS-II). In cyclic ADP accept the electron in presence of sun light in PS-I and ATP is formed ADP +Pi-----ATP + H2O). However, in Non-cyclic photophosphorylation, both PS-I and PS-II are involved both NADPH2 and O2 are generated as the end product.