Section 8.3 The Calvin Cycle (Dark Reactions)

Calvin Cycle Calvin Cycle Calvin Cycle: second biochemical pathway of photosynthesis that uses ATP and NADPH to form organic compounds

A) Carbon Fixation by the Calvin Cycle 1) Carbon Fixation: process where carbon atoms of CO 2 are fixed into organic compounds

A) Carbon Fixation by the Calvin Cycle 2) CO 2 diffuses into stroma - CO 2 + RuBP + enzyme = PGA

A) Carbon Fixation by the Calvin Cycle 2)PGA + ATP + NADPH = G3P

A) Carbon Fixation by the Calvin Cycle 3) Most G3P turns back into Compound and the rest form ______________

B) The Balance Sheet for Photosynthesis The Balance Sheet for PhotosynthesisThe Balance Sheet for Photosynthesis 1) Each rotation of the Calvin Cycle 1) __________________________ 2) ___ ATP and ____NADPH molecules are used up

B) The Balance Sheet for Photosynthesis 1) To make 1 molecule of G3P the Calvin Cycle must run 3x To make 1 molecule of G3P the Calvin Cycle must run 3x To make 1 molecule of G3P the Calvin Cycle must run 3x 2) Final equation for Photosynthesis: 6CO 2 + 6H 2 O + Energy  C 6 H 12 O 6 + 6O 2

1) What is carbon fixation? 2) What does fixation mean? 3) When does the Calvin Cycle occur? 4) What is the final equation for Photosynthesis?

2) Alternative Pathways 1) C 3 Plants- plants that fix Carbon only through the Calvin Cycle, Common plants: vegetables

Stomata Open and Closed

A) The C 4 Pathway 1) C 4 Pathway- pathway to fix CO 2 into 4- Carbon Compounds 1) Stomata will stay partially closed during hot days 2) Adapted to high temps and intense sun 3) Ex: Corn, sugar cane

B) The CAM Pathway 1) Stomata is open at night and closed during the day 2) CO 2 is taken in at night and during the day the carbon is fixed into the Calvin Cycle 3) Ex: Cactus, pineapple

D) Rate of Photosynthesis 1) Factors that affect the rate of Photosynthesis a) Amount of Light b) Temperature c) Amount of CO 2