1. Chapter 8
Photosynthesis

2. 8-2 Photosynthesis: An Overview
Timeline
1643 – Jan van Helmont
Experiment: Only gave plants water then took careful measures of the plants growth.
Conclusion: Plants gain most of their mass from water.

3. 8-2 Photosynthesis: An Overview
Timeline
1771 – Joseph Priestley
Experiment: A candle would only burn when placed in a bell jar as long as a plant was also in the bell Jar
Conclusion: Plants produce a substance needed to support burning (Oxygen).

4. 8-2 Photosynthesis: An Overview
Timeline
1779 – Jan Ingenhousz
Experiment: Place aquatic plants in water, then exposed then to conditions of light and no light. Plants produced bubbles when light was present
Conclusion: Aquatic plants will produce oxygen only when light is present.

5. 8-2 Photosynthesis: An Overview
Chemical Equation for Photosynthesis
6CO2 + 6H2O O2 + C6H12O6
Revised Formula
12H2O + 6CO O2 + C6H12O6 + 6H2O
Light
Chlorophyll
Light
Chlorophyll

6. Photosynthesis

7. Photosynthesis: Reactants and Products
Section 8-2
Light Energy
Chloroplast
CO2 + H2O
Sugars + O2
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8. 8-2 Photosynthesis: An Overview
Light & Pigments
Chlorophyll – Pigment in the Chloroplasts of plant cells that absorbs light energy.
Pigment: a substance which absorbs light.
2 Types of Chlorophyll
Chlorophyll a & Chlorophyll b
Work together to absorb all but green light waves (green is reflected which makes plants appear green).
Also contain Carotene – Pigment that reflects red, orange, and yellow (seen mostly in the Fall).

9. Figure 8-5 Chlorophyll Light Absorption
Section 8-2
Absorption of Light by
Chlorophyll a and Chlorophyll b
Chlorophyll b
Chlorophyll a V B G Y O R
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