Ch. 8 Photosynthesis

ENERGY & LIFE Autotrophs get energy they need to produce food from the sun (or a light source) ATP stores energy for cell activities like active transport & movement within the cell

PLANT EXPLORATION… Van Helmont: Plants need water to grow Priestley: Plants produce oxygen (O2) Ingenhousz: Plants need light to produce oxygen (O2)

Plants are green because of the pigment ______________ Plants are green because of the pigment ______________. (which absorbs light energy) CHLOROPHYLL During the fall, the green chlorophyll pigments are greatly reduced revealing the other pigments. Carotenoids are pigments that are either red or yellow.

Light vs. Pigments

Chloroplast Structures & Function: Locate the … Thylakoids Granum Stoma 2 stages of photosynthesis: Light-dependent reactions Calvin Cycle (Light-independent)

Light Dependent Reactions (Photosystems II and I) Light absorbed by chlorophyll (in Thylakoids) ADP converted to ATP Convert NADP+ to NADPH (Electron Carriers) Produce Oxygen (O2) gas

Calvin Cycle or Light independent reactions (Dark Reactions) CO2 enters from atmosphere Energy from ATP & NADPH used to convert 3-carbon molecule to higher energy Produces a single 6-carbon sugar molecule

Basic Process of Photosynthesis: CO2 Sun LIGHT Light Dependent Reactions Calvin Cycle CHRLORPLAST O2 Sugars

Factors that affect the rate of Photosynthesis are… Availability of Water Temperature Intensity of Light Concentration of CO2