Photosynthesis, the metabolic process that converts sunlight, water and carbon dioxide into sugars for growth and oxygen for the atmosphere. Without it animals would never have evolved on this earth! It evolved around 450 million years ago when organisms were rising to the surface of the oceans.
Photosynthesis provides the basis of life for plants. It is extremely complex and made up of two stages; the light dependent stage and the light independent stage. Both of which involve many intricate reactions and take place in chloroplasts located in plant cells.
Chloroplasts contain chlorophyll, where photons from light excite electrons, pushing them through an electron transport chain and resulting in ATP production for the plant. The best part about photosynthesis is the by-product, oxygen allows us to live.
From Crash Course: Biology on YouTube by Hank Green.