1. Independent and Dependent Reactions
Photosynthesis

2. Objectives You will be able to: Describe the process of photosynthesis
Describe light-dependent and light-independent reactions
You will demonstrate this by completing the following:
Power Notes
Chloroplast worksheet
Photosynthesis worksheet
5 question quiz

3. KEY CONCEPT The overall process of photosynthesis produces sugars that store chemical energy.

4. Photosynthetic organisms are producers.
Producers make their own source of chemical energy
Plants use photosynthesis and are producers
Photosynthesis captures energy from sunlight to make sugars 4

5. Photosynthesis Equation
Photosynthesis occurs in 2 stages
1 – Light Dependent Reactions
take place in the Thylakoid membrane
2 – Light Independent Reactions
take place in the Stroma
Photosynthesis Equation
Sunlight
6CO H2O C6H12O O2
Reactants
Products

6. Photosynthesis in plants occurs in chloroplasts
Photosynthesis takes place in two parts of chloroplasts
Grana (stacks of thylakoids)
Stroma
chloroplast
stroma
grana (thylakoids) 6

7. Inside the Chloroplast
Thylakoids
Membrane bound compartment
Light Dependent Reactions
Grana
Stacks of Thylakoids
Stroma
Fluid that surrounds the grana inside the chloroplast
Light Independent Reactions (Calvin Cycle)

9. Thylakoids
Stroma
Outer membrane
Lumen
Inner membrane
Granum

10. Light Dependent Reaction1
Solar energy (light) is absorbed by the chlorophyll in the chloroplast
Water molecules enter the thylakoid and are broken down into Hydrogen, Oxygen and Electrons.
Oxygen is released as a waste product into the atmosphere
Pg. 104

11. Light Dependent Reaction2
Electrons move along the Thylakoid membrane in the Electron Transport Chain (ETC).
Energy from Electrons used to make energy-carrying molecules: ATP and NADPH
Pg. 104

12. Light Independent Reaction
(Calvin Cycle) 3
Occurs in the Stroma – CO2 and energy from light dependent reactions (ATP and NADPH) are used to build sugars
Pg. 104

13. Light Independent Reaction
(Calvin Cycle) 4
Six-carbon sugars are formed – usually Glucose.
Pg. 104

14. The equation for photosynthesis is: 6CO2 + 6H2O  C6H12O6 + 6O2
Carbon Dioxide
Sugar
(glucose)
Oxygen
Water
How many molecules of Carbon Dioxide are needed to make a six-carbon sugar? 6 15

15. Flow of H+ ions through ATP Synthase makes ATP
Summary of light-dependent reactions
Energy is captured from sunlight by chlorophyll (pigments). The energy is transferred to electrons that enter the electron transport chain.
Water molecules are broken down into H+ ions, electrons and oxygen molecules. Water molecules provide the H+ ions and electrons used in light-dependent reactions.
Energized electrons provide energy for H+ ion transport, and they are added to NADP+ to form NADPH.
Flow of H+ ions through ATP Synthase makes ATP
Products are oxygen, NADPH, ATP. Oxygen flows to atmosphere as photosynthesis waste product. Energy from ATP and NADPH used in light-independent reactions (Calvin cycle) to make sugars from carbon dioxide.