Photosynthesis

What is Photosynthesis? The process where plants use energy from the sun to rearrange water molecules and carbon dioxide molecules to form sugars (mainly glucose) and oxygen molecules Plants DO NOT change sunlight into energy!!

The Chemistry of Photosynthesis 6CO2 + 6H2O ------------ > C6H12O6 + 6O2 CO2 is carbon dioxide H2O is water C6H12O6 is glucose O2 is oxygen Chlorophyll Sunlight

The Chemistry of Photosynthesis 6CO2 + 6H2O ------------ > C6H12O6 + 6O2 CO2 is carbon dioxide H2O is water C6H12O6 is glucose O2 is oxygen Chlorophyll Sunlight

The Role of Sunlight in Photosynthesis Sunlight is made of different energies (colors) of light Remember ROYGBIV from elementary school? Chlorophyll absorbs the red, blue and violet parts of sunlight and uses them to make energy

The Role of Chlorophyll Chlorophyll is a chemical pigment (color) that absorbs certain wavelengths of sunlight (especially red, blue and indigo) The energy that is absorbed is given to the electrons of the chlorophyll molecule These high energy electrons supply the starting energy for photosynthesis

Inside the Chloroplast Sac-like photosynthetic membranes called thylakoids Sacs are stacked into structures called grana Space between grana called stroma Proteins in thylakoids arrange chlorophyll and other pigments into groups called photosystems

Inside the Chloroplast

Overview of Photosynthesis

Photosynthesis Has Two Steps Light dependent reaction that requires sunlight Light independent reaction that does not require sunlight; can occur during daytime as well as at night

Light Dependent Reaction Produces oxygen gas (waste product) Produces ATP (stores energy) Produces NADP+ (carries electrons)

Dark Reaction Uses ATP and NADPH to produce high energy sugars

What are the reactants in photosynthesis? What are the products? What wavelengths of light are absorbed by chlorophyll? Why do green plants look green? What part of the chlorophyll molecule actually absorbs the energy from the sun? Define the following terms: thylakoid, grana, stroma, photosystem What are the products of the light reaction phase of photosynthesis? What are the products of the dark reaction phase of photosynthesis?