Calvin Cycle Chapter 8 Sec. 3

Photosynthesis Capturing energy from light and storing it within organic compounds Capturing energy from light and storing it within organic compounds

Two stages of photosynthesis: Light Rxns. and the Calvin Cycle

Chloroplast Thylakoid – small flattened sacs Thylakoid – small flattened sacs Grana – stacks of thylakoids Grana – stacks of thylakoids Stroma – fluid solution inside chloroplast Stroma – fluid solution inside chloroplast

Light Reaction Uses light energy to produce ATP and NADPH Uses light energy to produce ATP and NADPH Occurs in the thykaloid of chloroplast Occurs in the thykaloid of chloroplast

Melvin Calvin

Calvin Cycle Uses ATP and NADPH from light reaction to produce organic compounds (glucose) Uses ATP and NADPH from light reaction to produce organic compounds (glucose) Occurs in the stroma of chloroplast Occurs in the stroma of chloroplast

Calvin Cycle Takes CO 2, ATP, and NADPH an converts other carbohydrates into readily available sugars Takes CO 2, ATP, and NADPH an converts other carbohydrates into readily available sugars

Factors Affecting Photosynthesis Temperature Temperature Light Light Water Water

Alternative Pathways C 4 Pathway C 4 Pathway CAM Pathway CAM Pathway

C 4 and CAM Pathways Occur in plants that are found in hot dry climates Occur in plants that are found in hot dry climates Potential to lose water Potential to lose water

Stomata Small pores on the underside of the leaf Small pores on the underside of the leaf Absorb water and allow CO 2 inside and O 2 out Absorb water and allow CO 2 inside and O 2 out

Stomata If they close to keep water in then CO 2 levels decrease and O 2 levels increase If they close to keep water in then CO 2 levels decrease and O 2 levels increase BAD !!!! BAD !!!!

C4 Pathway CO2 is fixed into a 4 carbon compound CO2 is fixed into a 4 carbon compound Stomata is partially closed during the day to prevent dessication Stomata is partially closed during the day to prevent dessication

C 4 Pathway Corn, sugar cane, and crabgrass Corn, sugar cane, and crabgrass Only lose as half as much water as normal Only lose as half as much water as normal

CAM Pathway Cactuses and pineapple Cactuses and pineapple Only open stomata at night to gather CO 2 Only open stomata at night to gather CO 2 Lose less water than C 3 and C 4 Lose less water than C 3 and C 4