1. KEY CONCEPT The overall process of photosynthesis produces sugars (glucose) that store chemical energy.

2. Photosynthetic organisms are producers.
Producers make their own source of chemical energy.
Plants use photosynthesis to make their own food; therefore they are producers.
Photosynthesis captures energy from sunlight to make glucose (sugar).

3. Chlorophyll is a molecule that absorbs light energy.
chloroplast
leaf cell
leaf
In plants, chlorophyll is found in organelles called chloroplasts.

4. Photosynthesis in plants occurs in chloroplasts.
Photosynthesis takes place in two parts of chloroplasts.
grana (stacks of thylakoids)
stroma (fluid outside the thylakoid)
chloroplast
stroma
grana (thylakoids)

5. The light-dependent reactions (A. K. A
The light-dependent reactions (A.K.A. – Light Reactions) capture energy from sunlight.
take place in thylakoids
water and sunlight are needed (reactants)
chlorophyll absorbs energy
energy is transferred along the thylakoid membrane then to light-independent reactions
oxygen is released (product)

6. The light-independent reactions (A. K. A
The light-independent reactions (A.K. A. – Dark Reactions) make sugars (glucose).
takes place in stroma (fluid outside the thylakoid)
needs carbon dioxide from atmosphere
use solar energy to build a sugar (glucose)

7. The equation for the overall process is:
6CO2 + 6H2O  C6H12O6 + 6O2
C6H12O6
granum (stack of thylakoids)
thylakoid
sunlight
1 six-carbon sugar
6H2O
6CO2
6O2
chloroplast 1 2 4 3
energy
stroma (fluid outside the thylakoids)

8. There are two steps to photosynthesis:
Light-Dependent Reactions
Also known as Light Reactions
Occurs in the thylakoids of chloroplasts
Uses (Reactant): Water
Produces (Product): Oxygen
Light-Independent Reactions
Also known as Dark Reactions or Calvin Cycle
Occurs in the stroma of chloroplasts
Uses (Reactant): Carbon Dioxide
Produces (Product): Glucose
In order for these two types of reactions to take place the following is needed:
Sunlight
Chlorophyll
Energy (solar)
Both of these reactions take place in the CHLOROPLASTS of plant cells!