1) Photosynthesis is the process by which plants, algae, and some bacteria use sunlight, water and carbon dioxide to produce oxygen and energy in the form of ATP and sugars like glucose. 2) It is comprised of two stages - the light reaction which converts solar energy to chemical energy in the form of ATP, and the Calvin cycle which uses ATP to convert carbon dioxide and water into sugars. 3) The process occurs in chloroplasts within plant cells, and relies on chlorophyll to absorb sunlight and drive the creation of ATP and oxygen from water and carbon dioxide.

1. Photosynthesis (Life from ) 6H 2 O + 6CO 2 ----> C 6 H 12 O 6 + 6O 2 Light

2. A little background Grass  Caterpillar  Bird Autotroph  Heterotroph  Heterotroph All energy originates with Autotrophs Organisms autotrophs heterotrophs Make own food Obtain food from others

3. The fuel of living things ATP- Adenosine triphosphate Consists of Adenine 5-carbon sugar called ribose Three phosphate groups Key to ATP’s ability to release energy Adenine Ribose P P P

4. ADP ADP is a cousin of ATP Main differences ADP has 2 phosphates ATP has 3 ADP has less energy then ATP This is where The bond breaks To turn ATP into ADP ADP

5. The photosynthesis equation The process by which light energy is converted into chemical energy and stored in organic compounds Referred to as biochemical pathway 6H 2 O + 6CO 2  energy  C 6 H 12 O 6 + 6O 2 Reactants Products

6. Energy needs of Life All life needs a constant input of energy Heterotrophs (animals, fungi, most bacteria) get their energy from “eating others” consumers of other organisms consume organic molecules Autotrophs (plants, some bacteria) get their energy from “self” use sunlight energy to synthesize organic molecules

7. We will be looking at how autotrophs and how they synthesize these organic molecules through photosynthesis

8. Where does photosynthesis occur? In the chloroplasts! absorb sunlight & CO 2 make energy & sugar CO 2

9. Light: absorption spectrum Light reaction can perform work with wavelengths of light that are absorbed chlorophyll a — the dominant pigment — absorbs best in red & blue wavelengths & least in green other pigments with different structures have different absorption spectra

10. Chloroplasts Green because absorb light wavelengths in red & blue and reflect green back out THAT IS WHY PLANTS LOOK GREEN TO US! WE SEE WHAT IS RELFECTED.

11. Photosynthesis: Overall Equation This is the equation you are used to seeing, but this is not the whole story… + water + energy  glucose + oxygen carbon dioxide 6CO 2 6H 2 O C 6 H 12 O 6 6O 2 light energy  + + +

12. Photosynthesis Actually two separate reactions Energy building use sunlight make energy (ATP) Sugar building use ATP use CO 2 make sugars (C 6 H 12 O 6 ) Energy building reactions Sugar building reactions ATP ADP sugar sun CO 2

13. Energy Building Reactions O 2 H 2 O Energy Building Reactions sunlight ATP H 2 O ATP O 2 light energy  + + makes ATP energy releases oxygen as a waste product

14. Sugar Building Reactions sugars C 6 H 12 O 6 CO 2 Sugar Building Reactions ATP CO 2 C 6 H 12 O 6 ADP ATP  + + ADP builds sugars uses ATP cycles ADP back to make more ATP

15. Putting it all together sugars C 6 H 12 O 6 CO 2 ATP ADP H 2 O O 2 sunlight Sugar Building Reactions Energy Building Reactions Plants make both: ATP sugars CO 2 H 2 O C 6 H 12 O 6 O 2 light energy  + + +

16. So what does a plant need? Takes in CO 2 H 2 O light Releases O 2 Produced and moved around sugars roots shoot leaves

17. How can a leaf do this? Let’s briefly examine the leaf structure H 2 O CO 2 CO 2 O 2 H 2 O phloem (sugar) O 2 xylem (water) Stoma (pore/hole)

18. Stomata Function of stomata CO 2 in O 2 out H 2 O out guard cell Stomata (pore or hole)

19. Xylem carry water up from roots

20. Phloem: food-conducting cells carry sugars around the plant wherever they are needed new leaves fruit seeds

21. Putting it all together Making a living… sunlight leaves = solar collectors photosynthesis gases: CO 2 in & O 2 out stomata = gases in & out H 2 O roots take in water from soil pulled up by leaf evaporation nutrients roots take in from soil

22. How are cellular respiration and photosynthesis connected? Respiration Photosynthesis glucose + oxygen  carbon + water + energy dioxide C 6 H 12 O 6 6O 2 6CO 2 6H 2 O ATP  + + + + water + energy  glucose + oxygen carbon dioxide 6CO 2 6H 2 O C 6 H 12 O 6 6O 2 light energy  + + +

23. Energy cycle Photosynthesis Cellular Respiration O 2 CO 2 plants animals, plants ATP H 2 O sun The Great Circle of Life! glucose

24. Resources www.bio.kimunity.com Miller, Ken and Joe Levine. Prentice hall Biology . Pearson Education Inc. New Jersey, 2005.