There are two stages to photosynthesis, …show more content…
In light-dependent reactions, light energy from the sun is used to split water (photolysis) which has been taken in by plants. Water, when broken, makes oxygen, hydrogen, and electrons. These excited electrons in photosystem II are used to create a proton gradient. The ATP synthase in the thylakoids generates ATP using this proton gradient. When the electrons gets transported to photosystem I, they are used to reduce NADP+. Oxygen diffuses out of the plant as a waste product of photosynthesis. This all happens in the thylakoid membrane of chloroplasts. Overall, the light reaction uses solar energy to produce ATP, NADPH, and O2. The light dependent reaction (Calvin Cycle) take place in the stroma. Energy from the ATP and NADPH molecules generated by the light reactions drives a chemical pathway that uses the carbon in carbon dioxide to build a three-carbon sugar called glyceraldehyde-3-phosphate (G3P). Cells then use G3P to build a wide variety of other sugars (such as glucose) and organic molecules. Overall, the Calvin Cycle produces sugar (C6H12O6