DO NOW

1. DO NOW • Name the stages of cellular respiration and where it occurs • Where is the majority of the ATP produced? • What is the function of coenzyme A? 12Bio 2011

2. Fill in the following • The light reaction makes……….. And …………. Which are used in the Calvin cycle • The light reaction occurs in the …………… • The dark reaction occurs in the …………… 12Bio 2011

3. PHOTOSYNTHESIS Year 12 Biology (MAH) 12Bio 2011

4. What is Photosynthesis? • Write everything that you know in groups of two regarding photosynthesis • Share with the class 12Bio 2011

5. Basis of life? • Produces oxygen which all living things require. • Plants – bottom of the food chain 12Bio 2011

6. What is it? • Photosynthesis is the process by which plants convert LIGHT ENERGY into CHEMICAL ENERGY (compounds which can be used by the plants) • Light is captured by the pigment CHLOROPHYLL, found in the CHLOROPLASTS of leaves and stems of plants • Chlorophyll reflects GREEN light • “The ability of plants to make their own food” 12Bio 2011

7. Chloroplast structure 12Bio 2011

8. Where are they found? • Most chloroplasts are found in the palisade layer which is located close to the top of the leaf. This enables as much sunlight as possible to be absorbed and increases the efficiency of photosynthesis. 12Bio 2011

9. Photosynthesis equation 6CO2 + 6H2O ------ C6H12O6 + 6O2 SUNLIGHT CHLOROPHYLL 12Bio 2011

10. Carbohydrates 12Bio 2011

11. 12Bio 2011

12. THE STEPS • Photosynthesis takes place in two phases • Light phase: which occurs in the thylakoids (light dependent) • Calvin cycle (Dark phase): which occurs in the stroma (light independent) 12Bio 2011

13. 12Bio 2011

14. Light Reaction • Occurs on the grana • Light energy is used to do two things • Excite electrons (give them more energy) to energise electrons along an electron transport chain • Split water 12Bio 2011

15. Electron Excitation • When light strikes an electron in a chlorophyll molecule, the electrons gain enough energy to be channelled into electron transport chain • Here ATP is produced. As high energy electrons from chlorophyll pass down an electron transport chain they release energy and ATP forms 12Bio 2011

16. Photolysis – splitting of water • Water is split into hydrogen ions electrons and oxygen • Electrons used to replace those used in electron transport chain 12Bio 2011

17. LIGHT PHASE ENERGY USED TO DO TWO THINGS: • Split water into hydrogen and oxygen (Hydrogen goes to fill Hydrogen carrier NADP  NADPH2 • Some energy is used to charge up ADP ATP NADPH2 and ATP then move to the stroma for the Calvin Cycle 12Bio 2011

18. Dark Cycle/Calvin Cycle • Cycle beings by carbon dioxide being captured from the air and fixed into a molecule in the stroma • The Calvin cycle then reduces fixed carbon to glucose with the help of NADH2 and ATP from the light phase 12Bio 2011

19. STEPS • Carbon dioxide is attached to the five carbon sugar compound (Ribulose -1-5-biphosphate) by the enzyme Rubisco forming a SIX carbon compound. • The six carbon intermediate compound is UNSTABLE and breaks up into two molecules of PGA (3 Phosphoglycerate) • The PGA molecules are converted to PGAL (3-phosphoglyceraldehyde). This requires ATP and NADPH. The NADPH supplies H atoms and electrons needed for this reaction. The ADP and NADP are then ‘refilled’ by the light phase • The PGAL molecules are converted via a number of steps to glucose, cellulose, starch, disaccharides, lipids and amino acids ORwill be recycled through a variety of reactions to form Ribulose-1-5- biphosphate ready to accept another carbon dioxide. 12Bio 2011

20. Compounds plant requires including glucose 12Bio 2011

21. CLOZE Activity • In PAIRS fill in the gaps to the paragraph using the words provided 12Bio 2011

22. Photosynthesis summary Chemical energy (ATP) H2O CO2 Light dependent: - Light independent: (eventually) Reactive hydrogen (NADPH) O2 C6H12O6 12Bio 2011

23. Photosynthesis summary Chemical energy (ATP) H2O CO2 Light dependent: - Grana/thylakoid membranes - Water converted to oxygen - Light energy converted to chemical energy (ATP) Light independent: - Chloroplast stroma - Carbon dioxide converted to glucose - Requires chemical energy (ATP) - Requires reactive hydrogen (eventually) Reactive hydrogen (NADPH) O2 C6H12O6 12Bio 2011

24. 12Bio 2011

25. Compare/Contrast • Compare and contrast photosynthesis vs respiration • How many major steps? • Inputs • Outputs • Where occurs • Should take up at least one page in your book (Good for revision) 12Bio 2011

26. Compare and Contrast PHOTOSYNTHESIS RESPRIRATION 12Bio 2011

27. Comparing photosynthesis and respiration Both require membranes P.S. – thylakoid Resp – inner mitochondrialmembrane 3 major steps Occurs in chloroplasts Occurs in cytoplasmand mitochondria Produces O2 Consumes H2O Both have electrontransport chains Photosynthesis Respiration Both involve energy conversion Converts lightenergy to mobilechemical energy Produces H2O Consumes O2 Both involveATP and reactivehydrogen atoms Converts mobile chemical energy to ATP 2 major steps 12Bio 2011

28. What effects photosynthesis? • Enzymes • Temperature • Amount of carbon dioxide • Light intensity and wavelength • Chlorophyll and minerals • Absorption of carbon dioxide • Sufficient water • Use Bayley pg. 137 to describe factors that effect photosynthesis and describe what is the compensation point 12Bio 2011

29. TO DO!! • Make a poem/rap about photosynthesis and combine all knowledge regarding light phase and Calvin cycle • Look at these for inspiration • This will HELP you remember what you have learnt • Prepare to report to class 12Bio 2011

30. RELATIONSHIP BETWEEN PHOTOSYNTHESIS AND RESPIRATION?? 12Bio 2011

31. Carbon Dioxide Saturation 12Bio 2011

32. See an animation of Mitosis • Square dance • http://www.cellsalive.com/meiosis.htm 12Bio 2011