Photosynthesis

Trapping Energy from Sunlight Photosynthesis – is the process plants use to trap the sun’s energy and build carbohydrates, called glucose, that store energy Ultimate source of energy that powers cells

Overview Two Phases –Light dependent –Light independent Overall equation –6CO 2 + 6H 2 O -> C 6 H 12 O 6 + 6O 2 enzymes, light, chlorophyll

Chloroplasts and Pigments Chloroplast – cell organelle where photosynthesis occurs Chlorophyll – absorbs most wavelengths of light except green

Light Dependent Reactions Requires light Takes place in the thylakoid Light strikes chlorophyll Excites the electrons Goes through the first electron transport chain = ATP

Second Electron Transport Chain Goes through second electron transport chain NADP + + H -> NADPH Storage of energy

Restoring Electrons Water is split = photolysis Water molecule is split to produce two hydrogen ions, oxygen, and two electrons 2H 2 O -> 4H + + O 2 + 4e - This is how we get our oxygen Pg. 234 fig. 9.7

Light Independent Reactions Does not require light Calvin Cycle or Dark reaction Takes place in the stroma Energy from the light- dependent fuels Calvin Cycle Cycle – one of last molecules needed for first

Process One CO 2 enters the cycle Has to go through the cycle six times

Questions? 6CO 2 + 6H 2 O -> C 6 H 12 O 6 + 6O 2 enzymes, light, chlorophyll