1. Ch 8 Photosynthesis

2. Chemical Energy and ATP
energy is the ability to do work
cells use energy to build new molecules, contract muscles, and carry out active transport
w/o ability to obtain and use energy, life would cease to exist
adenosine triphosphate (ATP) – one of most important compounds cells use to store and release
cells release energy stored in ATP by breaking bonds between phosphate groups

3. Heterotrophs and Autotrophs
autotrophs - organisms that make their own food
photosynthesis - process by which autotrophs use the energy of sunlight to produce high-energy carbohydrates for food
plants, algae, and some bacteria are able to use light energy from the sun to produce food
heterotrophs - organisms that obtain food by consuming other living things
get food by: eating plants, feeding on plant-eating animals, or decomposing other organisms

4. Heterotrophs and Autotrophs

5. Light all energy everywhere originates from the sun
travels to Earth in the form of light
sunlight = different wavelengths, visible light spectrum: rainbow
compound that absorbs light absorbs energy
chlorophyll absorbs visible light very well

6. Pigments
plants gather the sun’s energy with light-absorbing molecules called pigments
principal pigment is chlorophyll
absorb light very well in all regions except green -> reflects green light -> why plants look green
colder temps -> chlorophyll breaks down, the red and orange pigments may be seen

7. Chloroplasts photosynthesis takes place inside chloroplasts
chloroplasts contain saclike photosynthetic membranes called thylakoids
arranged in stacks known as grana
chlorophyll located

8. An Overview of Photosynthesis
uses the energy of sunlight to convert H2O and CO2 (reactants) into high-energy sugars – glucose and oxygen (products)
plants use sugars to produce complex carbs (starches) that are used for energy