1. Ch 8 Photosynthesis 8.1 Energy and Life
8.2 Photosynthesis: an Overview
8.3 The reactions of Photosynthesis

2. 8.1 Energy and Life
Plants and some other types of organisms are able to use light energy from the sun to produce food
Organisms that can produce their own energy are called Autotrophs
Heterotrophs acquire their energy by consuming

3. 8.1 Energy and Life
One of the principle chemical compounds that cells use to store and release energy is Adenosine Triphosphate (ATP)
Energy release from converting ATP to ADP is commonly used for active transport, protein synthesis and muscle contraction

4. 8.1 Energy and Life
Energy is not stored as ATP but stored as sugars and carbohydrates, ATP is only produced at it is needed

5. 8.2 Photosynthesis: An Overview
In the Process of Photosynthesis, plants use the energy of sunlight to convert water and carbon dioxide into high energy carbohydrates (Sugar and Starches) and oxygen, a waste product
LIGHT
6CO2 + 6H2O > C6H12O6 + 6O2
carbon dioxide + water > sugars + oxygen

6. 8.2 Photosynthesis: An Overview

7. 8.2 Photosynthesis: An Overview
In addition to water and carbon dioxide, photosynthesis requires light and chlorophyll, a molecule in chloroplasts

8. 8.2 Photosynthesis: An Overview
Plants gather the suns energy with light absorbing molecules called Pigments
Plants principle pigment is Chlorophyll and comes in 2 varieties, Chlorophyll A and Chlorophyll B

9. 8.3 The reactions of Photosynthesis
Chloroplasts are an organelle in plants that contain
Grana- Consists of stacks of flattened sacs called Thylakoids
Surrounding the thylakoids is a fluid called Stroma

10. 8.3 The reactions of Photosynthesis
Proteins in the thylakoid membrane organize chlorophyll and other pigments into clusters called Photosystems

11. 8.3 The reactions of Photosynthesis
Along with ATP, the Calvin cycle needs Electrons to synthesis Sugar
NADPH is the carrier of electrons in a process called Electron Transport

12. 8.3 The reactions of Photosynthesis
The light-dependant reactions produce oxygen gas and convert ADP and NADP+ into the energy carriers ATP and NADPH
I)Light energy is absorbed by electrons and passed
II)Electrons transported from stroma to inner thylakaoid
III) NADP+ converted into NADPH
IV) Transfer of electrons creates a charge that produces ATP
V) Proteins in the membrane called ATP Synthase which allow H+ to balance the charge

13. 8.3 The reactions of Photosynthesis
The Calvin Cycle uses ATP and NADPH from the light-dependant reactions to produce high energy sugars
Many steps involved in the Calvin cycle are called the Light Independent Reactions

14. 8.3 The reactions of Photosynthesis
Factors that affect Photosynthesis:
Negative Factors
Not enough CO2
Not enough Light
Temperature too high or too low will denature Proteins
Positive Factors
More light, more photosynthesis but a Max can be reached
Pg 214 (1-5)