Question

What are some known inhibitors of photosynthesis and indicate at what location(s) precisely in the electron transfer reactions of photosynthesis does this compound inhibit. Provide at least one such compound.

Answer 1

Photosynthesis is a combination of numerous physichemical reactions in the plant (the pigment is chlorophyll)

The plan absrobs light and conver the energy through an electron transport system, and different multistep enzymatic pathway which help is conversion of carbon dioxide to carbohydrates and oxygen (which we need).

So there are many photosynthesis inhibitors which inhibits the phosynthesis pathway at different levels.

There are two photosynthesis systems in plant called as

PSI and PSII

So the inhibitors show their action on different centres of theses systems

Let us check the most common examples for reference (these are also used as herbicides)

a) Tirazine :

They bind with the sites adjacent to a specific protein (D-1 quinone) and hence block the electron transport system in photosynthesis.

b) Nitriles

R-CN

They also bind with the sites adjacent to a specific protein (D1-quinone) and hence block the ETS of photosynthesis

[They are also respiratory inhibitors , as KCN)