1. Chapter 8-3
Light Dependent and
Light Independent
Reactions

2. I. Basic Photosynthesis
A. Photosynthesis – the process by which autotrophs use light energy to turn carbon dioxide and water into glucose and oxygen
B. The basic equation for photosynthesis is as follows:
6CO2 + 6H2O C6H12O6 + 6O2
Sunlight

3. II. Photosynthesis Equation
A. USES: (reactants)
1. 6 Carbon Dioxide molecules(thanks to us) 
2. 6 Water molecules
B. IN THE PRESENCE OF
1. Sunlight
B. TO MAKE: (products)
1. 1 Glucose (for cell) molecule
2. 6 Oxygen molecules (given off as waste) lucky us 

4. III. Chloroplasts 1. Traps the E from sunlight.
A. Organelle where PS takes place in autotrophs
B. Contains chlorophyll (pigment that “traps” light)
1. Traps the E from sunlight.
2. Transfers the E to the electrons (e-) in chlorophyll.
3. They are then called “high energy” electrons

5. Inside a
chloroplast

6. Components of Chloroplast
Thylakoid – Saclike photosynthetic membranes
Light-dependent reactions occur here
Granum –single stack of thylakoids
Grana- All of the Granum in one Chloroplast
Stroma – Region outside the thylakoid membrane
Reactions of the Calvin Cycle occur here

7. C. LIGHT DEPENDENT: reactions take. place in the thylakoid membranes
C. LIGHT DEPENDENT: reactions take place in the thylakoid membranes of chloroplast.
D. LIGHT INDEPENDENT (dark/Calvin): reactions take place in the stroma of chloroplast.

8. PLANT CELL -
High Energy Sugar
Glucose

9. IV. Light Dependent Reactions
A. Requires light and water
B. Takes place in the Thylakoid

10. C. Uses energy from sun to form:
1. ATP- ( recharged ADP + P from Calvin cycle) used in the Calvin cycle.
2. Create NADPH- from NADP+:
NADP+ comes from the Calvin cycle and it’s job is to carry the high energy electrons and the H (from water splitting) to form NADPH-
3. Oxygen gas : waste given off to environment (remember it came from the water splitting)

11. D. Water is split to produce:
1. Oxygenwaste
2. Hydrogenused to convert NADP+ to form NADPH- which is used in the e- transport chain.

12. III. Light Independent (dark) Reactions
A. also called Calvin Cycle
B. Produces high energy sugars (glucose)
C. Uses ATP and NADPH- (from light reactions) to convert CO2 (from air) into
glucose.
D. Does not require light-uses E from ATP

13. IV. Factors that Affect rate of PS
A. No water = No NADPH
If no NADPH = No Glucose
B. Temperature- enzymes sensitive to extreme temperatures
C. Light Intensity:
in light = in PS (to a certain point)

14. Summary Light Dependent Reaction
Uses: Water + Light
To Make: ATP + NADPH- + (O2 as waste)
Light Independent Reaction (Calvin Cycle)
Uses: CO2 + ATP + NADPH-
To Make: glucose
***GLUCOSE IS MADE DURING DARK REACTIONS NOT LIGHT!!!!