Photosynthesis (net consumption of water) 6CO 2 + 6H 2 O C 6 H 12 O 6 + 6O 2 Light Chlorophyll
Photosynthesis (tracking atoms)
How Does CO 2 Get In The Plant? CO 2 enters the ____________ What is the source of CO 2 ? ______ Air 78.08 %N 2 20.95 %O 2 0.03 %CO 2 argon, helium, hydrogen, ozone, methane
How Does Water Get In The Plant? Water enters through the __________ Most water is lost from the plant through the _________ To reduce water loss leaves are covered with a waxy cuticle (plant “chapstick”)
CO 2 Enters The Leaf is Covered with a Waxy Cuticle: “Plant Chapstick ” H 2 O Exits If water cannot get out of the leaf through the waxy cuticle what cannot get into the leaf for P/S? Mesophyll cell or photosynthetic cell: Note the chloroplasts
Chlorophyll Chlorophyll is a green pigment Pigments absorb light energy The color you see is the color that is reflected Whiteversus Black Why is chlorophyll green? Would you expect green light to be an effective color of light for P/S?
Photosynthesis is a Two Step Process 6CO 2 + 6H 2 O C 6 H 12 O 6 + 6O 2 The Light Reactions: Light Dependant Photochemical Convert light energy into chemical energy The Light Independent Temperature Dependant Use the chemical energy created in the light reactions to convert CO 2 to glucose
Photosynthesis Overview (2 step process)
Locations of Reactions The Light Dependent Reactions occur on the grana The Light Independent Reactions take place in the stroma
High Potential Energy Molecules Is this an example of oxidation or reduction? (oxidation = loss of e-, reduction = gain of e-) Does the formation of NADPH require or release energy? NADP + + 2e - (2H)NADPH + H + P e-e- e-e- NADPH + H + NADP + +2e -
High Potential Energy Molecules Does the formation of NADPH require or release energy? NADP + + 2e - (2H)NADPH + H + NADPH + H + NADP + +2e - Reduction (endergonic) Oxidation (exergonic)
High Potential Energy Molecules Adenosine Triphosphate Adenosine Diphosphate + P + Energy High P.E.Low P.E. High P.E.
The Light Reactions Photochemical: Light energy is converted to chemical energy in the form of two high potential energy molecules.
The Light Reactions The Two High Potential Energy Molecules Produced are: __________ The Electron Source is?__________ When water gives up electrons what waste product is produced?
Figure 10.13a (a) How a photosystem harvests light Thylakoid membrane Photon Photosystem STROMA Light- harvesting complexes Reaction- center complex Primary electron acceptor Transfer of energy Special pair of chlorophyll a molecules Pigment molecules THYLAKOID SPACE (INTERIOR OF THYLAKOID) ee
Figure 10.18 STROMA (low H concentration) THYLAKOID SPACE (high H concentration) Light Photosystem II Cytochrome complex Photosystem I Light NADP reductase NADP + H To Calvin Cycle ATP synthase Thylakoid membrane 2 13 NADPH Fd Pc Pq 4 H + +2 H + H+H+ ADP + P i ATP 1/21/2 H2OH2O O2O2
Mitochondrion Chloroplast MITOCHONDRION STRUCTURE CHLOROPLAST STRUCTURE Intermembrane space Inner membrane Matrix Thylakoid space Thylakoid membrane Stroma Electron transport chain HH Diffusion ATP synthase HH ADP P i KeyHigher [H ] Lower [H ] ATP Figure 10.17