Photosynthesis(Autotrophic Nutrition)

How to plants make energy for themselves?

What is Photosynthesis

• Photosynthesis: process of using solar energy to generate glucose that plants can use to make energy.

Where does photosynthesis take place?

• Chloroplast: site for photosythesis– Contains chlorophyll: pigment that

activates photosynthesis & gives plants their green color

Stages of Photosythesis

• Light Reactions needs the sun and water

• Dark Reaction no light needed

Important parts of the cholorplastThykloids: site of Light rxns.

Grana: a bunch of thykloids

Stroma: site ofDark rxns.

• Light is used in order for split water in the thykloids.

• CALLED PHOTOLYSIS• Water molecule is split• Oxygen is freed into the atmosphere• Two hydrogen atoms from molecules drive:

NADPNADPHADP ATP

• These two high energy molecules go into stage 2 of photosynthesis

Step 1- Light Reactions

Copy and paste into browser

• http://www.stolaf.edu/people/giannini/flashanimat/metabolism/photosynthesis.swf

Step 2: Dark Reactions (PS1)

• Light is not required

• Takes place in the stroma

• Given the name CARBON FIXATION (Calvin Benson Cycle) BECAUSE IT WILL NOW FIX CARBON DIOXIDE CHEMICALLY TO FORM GLUCOSE

Copy and paste link into browser to observe dark reaction

• http://www.compulink.co.uk/~argus/Dreambio/photosynthesis/photosynthsis%20animation.htm

Overall Chemical Equation

• 6 CO2 +12 H2 O+ LIGHTC6 H12 O6+6 O2 + 6H2O

• REVERSE OF CELL RESPIRATION