Photosynthesis

The Transfer of Light energy into chemical energy

Sections 4.2-4.3

The purpose of plants

Convert inorganic to organic

Foundation of food web- autotrophs

Shelter

Energy

Medicine

Soil Stability

Adaptations: allowed plants to move on to

land not present in non-vascular plants

Mycorrhizae fungus- in 80% of plants

Pollen grains

Stomata

Cuticle-waxy

Vascular tissue

Xylem- non-living, water from roots

Phloem- living, food to roots

Rate of PhotosynthesisAvailability of raw materials

Temperature 68-95oF (20-35oC)- below or above enzyme activity decreases

Intensity of sunlight

Rate levels off at a given

intensity

ChlorophyllThe pigment that absorbs the sunlight

Chlorophyll absorbs in the blue,

violet and red

spectrum but reflects green light

You see the wavelength reflected

Anatomy of a chloroplast

Stroma

Thylakoid

The Balanced Equation

6CO2 + 12H2O C6H12O6 + 6O2 +

6 H2O

Sunlight

Reactants Products

Graphic Overview of Photosynthesis

The Players• CO2, H2O, O2, C6H12O6 sunlight

• NADPH, ATP - energy molecules• NADP+, ADP - potential energy

NADP+ NADPH

Light Dependent ReactionTakes Place in the Thylakoid Membrane

Pigment in photosystem II transfers energy to photosystem I

Energy is used by NADP+ to become NADPH

H+ from oxidation of water convert ADP to ATP

2H2O 4H+ + O2

The Dark ReactionThe Calvin Cycle

Takes place in the stroma, does not require light

Energy for reaction is provided by NADPH and ATP

from light reaction

Forms Glucose

6CO2 + 12H2O C6H12O6 + 6O2 + 6

H2O

Sunlight

Light Reaction

H2O + NADP+ + ADP + P NADPH + ATP + O2+ H2

Dark Reaction

NADPH + CO2 C6H12O6 + H2O + ADP + NADP+

Remains in chloroplast

Light Reaction

Dark Reaction

ATP

Sunlight