The purpose of photosynthesis is to make glucose from sunlight.
Like this image displays, plants take in sunlight and carbon dioxide. After plants take in sunlight and carbon dioxide they release oxygen to be able to provide to the environment. What happens in plants is that they take in energy in the form light in both light reactions and calvin cycle.
To go more in depth, light and water go through the light reactions.and release oxygen. The calvin cycle, which takes place in the stroma, takes in carbon dioxide, ATP, NADPH, and releases sugars for plants to use.
Inside the thylakoid membrane, the light goes through the photosystem 2 and through photosystem 1. Inside the photosystems there is chlorophyll which helps absorbs light.
The water that the plant absorbs is broken down into oxygen and hydrogen.
An electron from the water that the plant absorbs goes through the photosystem 2 and eventually makes its way up to create NADPH.
The other electrons actually help pomp more protons throughout the thylakoid membrane.
Eventually there too many protons, that there's no where else for them to go. Thus leading to them going through the protein ATP Synthase to help create ATP.
Respiration
Glycolysis
Starts off with glucose and results into pyruvate
Occurs outside of mitochondrion
Krebs Cycle
Takes the carbon from the pyruvate and relese that as carbon dioxide
Stores energy as NADH and FADH2
Electron Transport Chain
Takes NADH and FADH and transfroms energy throught the electron transport chain.
Pumps protons to the outside of the inner membrane, and the build up of that leads into it goinginto the ATP Synthase to create ATP.
An electron from NADH and FADH is going to combine with oxygen and hydrogen to create water, and what helps pull this electron out of FADH and NADH is oxygen because it pulls the electron to itslef.