Photosynthesis If you were an alien and could only learn one thing about life on earth this would be it

It starts with the Sun Sunlight and the spectrum of visible light Chlorophyll is an amazing molecule

Light dependent reactions Light adsorbed by the photosystems produces high energy electrons in chlorophyll, ATP and NADPH are produced To replace electrons in chlorophyll enzymes in the photosystem membrane split water in 2H and O (for every 2 molecules of water the cell gets 4H and 2O). Nearly all the O2 on earth is from this reaction

Light independent reactions Energy from ATP and NADPH is converted to sugar Called the Calvin Cycle Starting material is CO2 and H2O

Light independent reactions Each set of reactions in the Calvin cycle uses one C from CO2, after three turns ½ a glucose molecule is built, 6 turns and a 6C is produced. This reaction is called fixing carbon because it removes carbon from the inorganic world and makes it organic

Photosynthesis Plants uses this glucose for their own energy needs and for storage Summary reaction: 6CO2 + 6H2O + Energy  C6H12O6 + 6O2