Photosynthesis
 Photosynthesis is the process by which
plant cell’s capture energy in sunlight
and use it to make food.
 Autotrophs are organisms that make
their own food.
 Heterotrophs are organisms that cannot
make their own food.
 During photosynthesis, plants use
energy from the sun to convert carbon
dioxide and water into oxygen and
sugars.
light energy
 6 CO2 + 6 H2O
Carbon dioxide
water
C6H12O6 + 6 O2
sugar
oxygen
Respiration
 Respiration is the process by which cells
obtain energy from glucose.
 During photosynthesis, cells “save”
energy in the form of carbohydrates,
during respiration cells “withdraw” the
energy by breaking down the
carbohydrates.
 During respiration, cells break down
simple food molecules such as sugar and
releases the energy they contain.
 C6H12O6 + 6O2
sugar
oxygen
6CO2 + 6H2O + energy
carbon
dioxide
water