1. PHOTOSYNTHESIS

3. Membrane holding together Thylakoids & Grana is called the LAMELLAE

4. THYLAKOID MEMBRANE THYLAKOID SPACE or LUMEN

5. PIGMENTS ARE IMBEDDED IN THE MEMBRANE IN CLUSTERS CALLED PHOTOSYSTEMS

6. REMEMBER THAT VISIBLE LIGHT IS ONLY A SMALL PORTION OF THE ENERGY COMING FROM THE SUN THE AMOUNT OF ENERGY IN LIGHT IS DETERMINED BY ITS WAVELENGTH  THIS ALSO DETERMINES THE COLOUR OF LIGHT

7. THE JOB OF PIGMENTS IS TO ABSORB SPECIFIC WAVELENGTHS OR PHOTONS OF LIGHT. THIS ENERGY IS TRANSFERRED TO ELECTRONS  THESE ‘catching’ PIGMENTS ARE CALLED ANTENNA COMPLEXES

9. PHOTOSYNTHESIS OVERVIEW LIGHT REACTIONS DARK REACTIONS

10. LIGHT REACTIONS

11. THE EXCITED ELECTRONS THEN TRANSFER ENERGY FROM PIGMENT TO PIGMENT IN THE PHOTOSYSTEM UNTIL IT REACHES A REACTION CENTRE (chlorophyll a) AN ELECTRON IS THEN ‘KICKED’ TO A HIGHER E-LEVEL REDOX REACTIONS THEN MOVE THE ELECTRON TO A “PRIMARY ELECTRON ACCEPTOR” CALLED PLASTOQUINONE or PQ  I.O.U. CONCEPT !!!!!

14. ENERGY HAS BEEN TRANSFERRED FROM SOLAR OR RADIANT ENERGY (light) INTO CHEMICAL POTENTIAL ENERGY ( PQ ) JUST AS IN THE ETC IN RESPIRATION THE ELECTRONS ARE THEN MOVED FROM ONE PROTEIN TO ANOTHER ALONG THE MEMBRANE (PQ  CYTOCHROME COMPLEXES  PLASTOCYANIN Pc  P700  FERREDOXIN Fd) THIS CAUSES H+ TO BE PUMPED INTO THE LUMEN

15. EVENTUALLY THE ELECTRONS REACH NADPH REDUCTASE – WHICH ATTACHES THE ELECTRONS AND SOME H+ TO NADP+ CREATING NADPH H+ THAT BUILDS UP IN THE LUMEN CREATE AN ELECTROCHEMICAL GRADIENT . AS THIS EQUALIZES THE H+ PASS THROUGH ATP Synthase AND CATALYZE ADP + Pi  ATP

17. “ Z DIAGRAM” A B

18. “ Z DIAGRAM”

23. PHOTOSYNTHESIS OVERVIEW LIGHT REACTIONS DARK REACTIONS

24. DARK REACTIONS

28. THE ENZYME RUBISCO CATALYZES THE FIXATION OF ATMOSPHERIC CO2 INTO THE TWO 3-PG MOLECULES IT WORKS VERY SLOWLY AND MANY COPIES ARE NEEDED TO MAKE THE PROCESS POSSIBLE RUBISCO MAY ACCOUNT FOR UP TO ½ THE PROTEIN IN A LEAF  EXTREMELY ABUNDANT

29. C-FIXATION RUBSICO REDUCTION REGENERATION

31. C-FIXATION RUBSICO REDUCTION REGENERATION

33. C-FIXATION RUBSICO REDUCTION REGENERATION C3 PHOTOSYNTHESIS

35. TWISTS

37. IN PLANTS WHERE H20 LOSS IS A SERIOUS PROBLEM (DESERT PLANTS) CAM PHOTOSYNTHESIS OCCURS LEAVES OPEN AT NIGHT AND STORE C02, DO C-FIXATION AND THEN STORE THE C4 PRODUCTS TO BE USED DURING THE DAY IN THE CALVIN CYCLE (C3)

38. THE END