Non-cyclical light phase of photosynthesis

In this video I will explain the non-cyclic light phase, photosynthesis.

The acyclic light phase begins with the arrival of photons to the photosystem II. It excites its target pigment P680 which loses as many electrons as photons it absorbs. After this excitation there is a continuous passage between molecules capable of gaining and losing those electrons.

But to replace the electrons that the pigment P680 lost, the hydrolysis of water (photolysis of water), giving off oxygen. This process is carried out on the inner face of the thylakoid membrane.

Finally, electrons are introduced into the thylakoid by cytochrome b-f and create an electrochemical potential difference (Mitchell's chemosmotic hypothesis) on both sides of the membrane. This expels protons through ATP synthetases with the consequent synthesis of ATP that accumulates in the stroma (ADP phosphorylation).

In the video you will be able to understand better the non-cyclic light phase, photosynthesis. In addition, if you are not sure you can continue practicing with problems of this type you can do the

printable exercises with their solutions that I have left you on the web. Good luck in your studies!