1. Life’s ultimate reaction
PHOTOSYNTHESIS

2. Photosynthesis
The definition: A process in which light energy, water and carbon dioxide are used to create glucose for energy. Photo= light Synthesis= to make All of life stems from this reaction!

3. Photosynthesis + + + The Chemical Equation 6 CO2 6 H2O C6H12O6 6 O2
Name: ______________________________________ Date: _____________________ #______
Photosynthesis
The Chemical Equation
6 CO H2O C6H12O O2
Energy + +
Carbon
dioxide +
water
Energy
glucose
oxygen

4. Photosynthesis
Photosynthesis takes place in the chloroplasts. Only the cells of the leaf have chloroplasts.
In eukaryotic cells, the chloroplasts contain specialized light-absorbing pigments.
Chloroplast

5. Structure of the Chloroplast
The chloroplast is the organelle in which photosynthesis takes place (animal cells do not have chloroplasts).
It is a double-membrane organelle.
It is green because it contains chlorophyll.
1 granum= one stack of thylakoids (disc-shaped structures)
Grana= multiple granum
*Lumen= space inside the thylakoids

6. Let’s Review: 1. Write the equation for photosynthesis:
6CO2 + 6H2O + Energy  C6H12O6 + 6O2
2. Are plant cells eukaryotic or prokaryotic?
3. Where in the plant does photosynthesis take place?
In the Chloroplasts that are found in the leaves
(chlorophyll makes it look green)

7. Let’s Review: Label the Chloroplast4.
Stroma
Inner membrane
Outer membrane
Granum
Thylakoid

8. Photosynthesis: The Chemical Process
Occurs in two main phases.
Light reactions
Dark reactions (aka – the Calvin Cycle)
Light reactions are the “photo” part of photosynthesis. Light is absorbed by pigments.
Dark reactions are the “synthesis” part of photosynthesis. Trapped energy from the sun is converted to the chemical energy of sugars.

9. Light Reactions- Overview
Light reactions occur in the thylakoid of the chloroplast.
Light energy and water are required for this process.
Energy storage molecules are formed. (ATP and NADPH)
Oxygen gas is made as a waste product.

10. Let’s Review: Light Reactions
5. Light reactions are the “_____________” part of photosynthesis. Light is absorbed by pigments. 6. Where do the light reactions occur? Thylakoid of the Chloroplast 7. What are the reactants and waste products in the light reaction? Water + Sunlight Energy  Oxygen 8. What else is made during the light reaction? Energy storage molecules called ATP and NADPH to be used in the Dark Reaction
Photo

11. Dark Reactions- Overview
Dark reactions (light-independent) occur in the stroma.
Carbon dioxide is “fixed” into the sugar glucose in a process known as carbon fixation
ATP and NADPH molecules created during the light reactions power the production of glucose.

12. Let’s Review: Dark Reactions
9. Dark reactions are the “_____________” part of photosynthesis. Trapped energy from the sun is converted to the chemical energy of sugars.
10. Where do the dark reactions occur?
Stroma
11. What are the reactants and waste products in the dark reaction?
Energy + Carbon Dioxide  Glucose
(ATP & NADPH)
Synthesis

13. Let’s Review: Light and Dark Reactions
12. Fill in the table below:
3. Where do the light reactions occur?
The thylakoid membranes
Reactants
Products
Light Reactions
Dark
Reactions
Water +
Sunlight Energy
 Oxygen
Carbon Dioxide +
(ATP & NADPH Energy)
 Glucose

14. Recap: Photosynthesis occurs in the chloroplast of the plant cell
Light reactions are in the thylakoids of the chloroplast
Dark reactions are in the stroma of the chloroplast
- 6CO2 + 6H2O + Energy  C6H12O6 + 6O2
Key
Light Reactants =
Dark Reactants =
Products =

15. Factors that Affect Photosynthesis
Sunlight - the amount of sunlight available and the color of the light (plants do not use green light- they reflect it). Temperature - as temperature increases, photosynthesis will increase but only up to a certain point (higher temperature mean higher rate of transpiration [water loss]). Availability - of water and carbon dioxide.