1. 8.1 Energy and Life

2. Autotrophs  Plants and some other types of organisms are able to use the energy of sunlight to turn water and CO 2 into Sugar Starch Oxygen

3. Chemical Energy and ATP  Energy comes in many forms Light, heat, electricity, and chemical compounds  Adenosine Triphosphate (ATP)- one of the main chemical compounds cells use for energy  Storing Energy Adenosine diphosphate (ADP)

4. Chemical Energy and ATP  Releasing Energy Break bond of the third phosphate on ATP ATP ADP  Think of ATP as a fully charged ADP battery

5. 8.2 Photosynthesis: An Overview

6. Investigating Photosynthesis  Van Helmot’s Experiment (1643)- concluded that trees take most of their mass from water

7. Investigating Photosynthesis  Priestley’s Experiment (1771)- found that plants release oxygen

8. Investigating Photosynthesis  Ingenhousz’s Experiment (1779)- found that aquatic plants need sunlight to release oxygen

9. The Photosynthesis Equation  Photosynthesis uses light to convert water and CO 2 into high-energy sugars and oxygen.

10. Light and Pigment  Photosynthesis also requires light and pigments  The main pigment in plants is called chlorophyll Chlorophyll a Chlorophyll b  Why do you think most plants appear green?

11. 8.3 The Reactions of Photosynthesis

12. Inside a Chloroplast  Thylakoid Membranes- photosynthetic sacs Stacks called grana  Protiens in the thyloakoids organize pigments into clusters called photosystems  Stroma- region outside the thylakoids Calvin cycle

13. Electron Carriers  Light excites electrons in chlorophyll  NADP+ accepts and holds 2 high energy elections and a H+ Converts NADP+ to NADPH Traps energy from light into chemical form

14. Light-Dependent Reactions  The light dependent reactions produce oxygen gas and convert ADP and NADP into the energy carriers ATP and NADPH  ATP synthase – large protein that uses energy from H+ ions to bind ADP and a phosphate group together to produce ATP

15. Calvin Cycle  Light independent  Use energy in ATP and NADPH from the light dependent reactions to produce high energy sugars

16. Factors Affecting Photosynthesis  Water supply – shortage of water will slow down and even stop photo.  Temperature – photo. Requires enzymes that only work in a narrow range of temp.  Light intensity – rate of photo. Increases as light intensity increases.