1. pHOTOSYNTHESIS
HOW PLANTS MAKE FOOD

2. Autotrophs and Heterotrophs
Organisms able to use light energy from the sun to produce food
Example: plants
Organisms that cannot use the sun’s energy directly to obtain energy
Example: animals

3. Energy Forms of energy: light, chemical, electrical, heat
ATP – adenosine triphosphate
Fuels cellular activities
Consists of adenine (contains N), ribose (sugar), and three phosphate groups

4. Energy When used, it loses a phosphate: becomes ADP
Full vs. used battery
Can be recharged
Examples of uses: active transport, movement of organelles within the cell along microtubules

5. An Overview:
Plants use sunlight to convert water and carbon dioxide into oxygen and carbohydrates.
Wavelengths of light are seen as different colors.
Plants gather energy from light using molecules called, “pigments.”

6. An Overview: Chlorophyll is the primary pigment (types a and b)
It absorbs red and blue well, reflects green
Other plant pigments (carotenoids and anthocyanins) are also present in leaves
They make the beautiful fall colors!
Light energy absorbed by chlorophyll excites electrons that power photosynthesis