Photosynthesis: The Calvin Cycle Life from Air 2007-2008

Remember what it means to be a plant… Need to produce all organic molecules necessary for growth carbohydrates, lipids, proteins, nucleic acids Need to store chemical energy (ATP) produced from light reactions in a more stable form that can be moved around plant saved for a rainy day + water + energy  glucose + oxygen carbon dioxide 6CO2 6H2O C6H12O6 6O2 light energy  +

  build stuff !! photosynthesis Light reactions Convert solar energy to chemical energy ATP NADPH What can we do now? ATP  energy  Stored power   build stuff !! photosynthesis

CO2 C6H12O6 What is the goal? Want to make C6H12O6 synthesis How? From what? What raw materials are available? CO2 CO2 contains little energy because it is fully oxidized Reduce CO2 in a series of steps to synthesize a stable energy storage molecule NADPH reduces CO2 carbon fixation NADP NADP C6H12O6

Calvin Cycle = “Dark Reactions” CO2 is going to be converted into glucose during the Calvin Cycle This is often referred to as the “Dark Reactions” Calling it the “Dark Reactions” is misleading It doesn’t only happen in the dark, but rather in the light AND dark! Remember light reactions can only happen in the light!

From Light reactions to Calvin cycle Takes place in the chloroplast stroma (which is like the cytoplasm of the chloroplast) Need products of light reactions to drive the Calvin cycle ATP NADPH stroma ATP thylakoid

Calvin Cycle summary Calvin cycle Consumed (used) CO2 Produced (made) glucose Regenerated (recycled) ADP Regenerated NADP ADP NADP

Putting it all together CO2 H2O C6H12O6 O2 light energy  + H2O CO2 Plants make both: energy ATP & NADPH sugars sunlight ADP NADP Energy Building Reactions Sugar Building Reactions NADPH ATP O2 sugars

The Great Circle of Life,Mufasa! sun Energy cycle Photosynthesis CO2 H2O C6H12O6 O2 light energy  + H2O plants CO2 glucose O2 animals, plants CO2 H2O C6H12O6 O2 ATP energy  + Cellular Respiration ATP The Great Circle of Life,Mufasa!

If plants can do it… You can learn it! Ask Questions!! 2007-2008