Download 2.1 Photosynthesis I. sources of energy A. Photosynthesis 1. process

2.1 Photosynthesis
I. sources of energy
A. Photosynthesis
1. process by which a cell captures energy in sunlight and uses it make food
2. photo means “light”, and synthesis means “putting together”
3. all things obtain energy directly or indirectly from sunlight energy
captured during photosynthesis
B. an autotroph makes its own food
C. heterotrophs obtain food by eating other organisms
D. plants and animals use energy from the sun to convert carbon dioxide and water
into oxygen and sugars
II. two stages of photosynthesis
A. capture the sun’s energy
1. occurs in leaves
2. pigment is colored chemical compound that absorbs light
3. main photosynthetic pigment in chloroplasts is chlorophyll
B. using energy to make food
1. two raw materials: water and carbon dioxide enter and move into the
chloroplasts
2. water enters through roots
3. carbon dioxide enters through stomata
4. a series of chemical reactions produce chemical products
a. produce six carbon sugar and oxygen
b. plants use sugar, to carry out cell functions, and release oxygen
C. photosynthesis equation
6CO2 + 6H2O--------- C6H12O6 + 6O