The Importance of Light and Water
(Plastids, 2015)
Here we have the Electron Transport Chain...but for plants
Now the Electron Transport Chain in Cellular Respiration started with HIGH enegry NADH+H+ and FADH2. This one for photosynthesis starts with LOW energy water.
Think of this like a party. Water doesn't have a lot of energy to get the party started. So that is where light plays a key role....
1. Light hits Photosystem II (aka P680) through photons .... this makes the electrons in PII EXCITED, as they travel along a similar relay of oxidizing and reducing. Basically: Light gets the party started.
2. Now that the electrons got excites, they ditched PII! But that is where water plays it's important role. Water keeps the party going by supplying electrons to PII through the WATER SPLITTING COMPLEX