1. Photosynthesis: An Overview

2. Photosynthesis Plants use the energy of sunlight to convert water and carbon dioxide into high-energy carbohydrates Photosynthesis Equation:

3. Scientist Investigation Jan van Helmont (1643) Joseph Preistley (1771) Jan Ingenhousz (1779)

4. Van Helmont’s Experiment Measured plant’s water intake and mass increase Concluded that trees gain most of their mass from water

5. Joseph Priestley Experiment Used a jar, candle, flame, and mint leaf Concluded that plants give off oxygen

6. Ingenhousz’s Experiment Concluded that light is necessary to produce oxygen

7. What the Experiments Led to: Other experiments: Discovered that in the presence of light, plants transform carbon dioxide and water into carbohydrates, and they also release oxygen

8. Process of Photosynthesis A plant transforms carbon dioxide and water Using light energy Gives off Oxygen and produces Glucose (a valuable source of energy)

9. Plants use low-energy raw materials to produce high-energy sugars Must look at how plants capture energy from then sun Plants gather the sun’s energy with light absorbing molecule~ PIGMENTS The plants’ principle pigment is chlorophyll a and chlorophyll b

10. Why are plants typically green? ROYGBIV Chlorophyll absorbs light waves of all colors Reflects the green light