Photosynthesis Review

The Cyclical Pathway of Photosynthesis Uses p700 to excite pigment electrons Excited electrons are passed down an electron transport chain via redox reactions A proton gradient is generated ATP synthase is used to produce ATP

The Non Cyclical Pathway of Photosynthesis Electrons are drawn from water and excited through photolysis at p680 Electrons are used to create a proton gradient for ATP synthase Electrons are reenergized at p700 and added to NADP+ to produce NADPH The end products ATP and NADPH can now be used to create G3P and glucose in the Calvin Cycle

- This diagram shows the location of the light dependent reactions All components of the light reactions are found embedded in the thylakoid membrane of the chloroplast The proton gradient is build inside the thylakoid lumen The end products ATP and NADPH are released into the stroma The Calvin Cycle takes place in the stroma

Each turn of the Calvin cycle fixes one molecule of CO2 Every three turns produces one molecule of G3P It takes 2 G3P to make one glucose (i.e. 6 turns of the Calvin cycle) In this process, the energy stored from the light reactions in the form of ATP and NADPH is used to produce glucose

CO2 is fixed ultimately into glucose (C6H12O6) H2O is being split to produce O2 as an electron donor