Photosynthesis: Photosystem ll

Question

What is the effect of temperature on Photosystem II's electron transfer rate and efficiency the presence of inhibitors, such as herbicides specifically glyphosate?

Answer 1

Hi Alyna,

Temperature affects Photosystem II and its processes, especially high temperatures. When the temperature is high, damage occurs in Photosystem II the oxygen-evolving complex (OEC), and electron transport at both the donor and acceptor site thus activity is reduced.

Herbicides are photosynthesis inhibitors by binding to D1 proteins in the photosystem II complex in the chloroplast. By binding to these proteins, herbicides block electron transport and stop CO2 fixation and the production of energy needed for plant growth. Remember that transfer of electrons from Photosystem II to Photosystem I is essential for the production of photosynthetic energy. Additionally, blocking electron transport cause the formation of highly reactive molecules that initiate a chain of other reactions causing lipid and protein membrane destruction.

Hope this helps

-Danielle