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

2. 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.

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 membranes
called thylakoids
Thylakoids contain
chlorophyll and other
light abosrbing
pigments
Stroma
The space surrounding
the grana
chloroplast
stroma
grana (thylakoids)

5. Photosynthesis takes place in 2 stages
Light Dependent Reactions
Energy from sunlight is absorbed and converted to chemical energy (ATP & NADPH)
Water molecules are broken down, oxygen is released as a waste product
Light Independent Reactions
Also called the Calvin Cycle
ATP and NADPH are used in the manufacture of carbohydrates from carbon dioxide in the air

6. The light-dependent reactions capture energy from sunlight.
take place in thylakoids in groups of molecules called photosystems
water and sunlight are needed
chlorophyll absorbs energy
energy is transferred along thylakoid membrane then to light-independent reactions
oxygen is released

7. The light-independent reactions make sugars.
take place in stroma
needs carbon dioxide from atmosphere
use energy to build a sugar in a cycle of chemical reactions

8. The second stage of photosynthesis uses energy from the first stage to make sugars.
Light-independent reactions occur in the stroma and use CO2 molecules.

9. 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)