1. Cellular Respiration Harvesting Chemical Energy
ATP

2. “Burn fuels” to make energy
CO2 + H2O + heat
fuel (carbohydrates) O2
cellular respiration
making ATP energy (& some heat) by burning fuels in many small steps
Movement of hydrogen atoms from glucose to water
ATP
food (carbohydrates) O2
ATP + CO2 + H2O (+ heat)

3. Animals are energy consumers.
What do we need energy for?
synthesis (building for growth)
reproduction
active transport
movement
temperature control (making heat)
Which is to say… if you don’t eat, you die… because you run out of energy.
The 2nd Law of Thermodynamics takes over!

4. Where do we get energy? ATP Energy is stored in organic molecules
carbohydrates, lipids, proteins
Animals eat these organic molecules  food
digest food to get
fuels for energy (ATP)
raw materials for building more molecules
ATP
We eat to take in the fuels to make ATP which will then be used to help us build biomolecules and grow and move and… live!
heterotrophs = “fed by others”
vs.
autotrophs = “self-feeders”

5. Adenosine TriPhosphate
What is energy in biology?
ATP
Adenosine TriPhosphate

6. Harvesting energy stored in food
Cellular respiration
breaking down food to produce ATP
in mitochondria
using oxygen
aerobic
usually digesting glucose
ATP
food O2
Movement of hydrogen atoms from glucose to water

7. Where does cellular respiration take place?
animal cells
plant cells