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Light Reactions

Light Reactions
The Calvin Cycle
Cellular Respiration
Glycolysis and Fermentation
Aerobic Respiration


The light reactions, which take place in the thylakoid membrane, use energy from sunlight to produce ATP and NADPH, and oxygen.

Step 1: Light energy forces electrons to enter a higher energy level in the two chlorophyll a molecules of photosynthesis II.
Step 2: Because molecules have been lost the chlorophyll a molecules have undergone an oxidation reaction. Each oxidation reaction must be accompanied by a reduction reaction. So, a substance have to accept electrons that the chlorophyll a molecules have lost.
Step 3: The primary electron acceptor donates that electron to the first of the series of molecules located in the thylakoid membrane. Those moles are called an electron transport chain. 
Step 4: Light is absorbed by photosytem I, which happens at the same time that light is absorbed by Photosystem II.
Step 5: NADP+ is reduced to NADPH by a reaction called oxidation/reduction reactions.