2. Cellular Respiration Harvesting Chemical Energy ATP

3. Energy needs of life  Animals are energy consumers  What do we need energy for?  synthesis  reproduction  active transport  movement  temperature control

4. Where do we get energy?  Energy is stored in organic molecules  carbohydrates, fats, proteins  Animals eat these organic molecules  food  digest food to get  fuels for energy (ATP)  raw materials for building more molecules  carbohydrates, fats, proteins, nucleic acids

5. ATP What is energy in biology? Whoa! Hot stuff!

6. Harvesting energy stored in food  Cellular respiration  breaking down food to produce ATP  in mitochondria  using oxygen  formula shows glucose, but that is just an example  could be other sugars, fats or proteins glucose + oxygen  carbon + water + energy dioxide C 6 H 12 O 6 6O 2 6CO 2 6H 2 OATP  + +++ heat

7. What do we need to make energy?  The “Furnace”  mitochondria  Fuel  food  carbohydrates, fats, proteins  The Helpers  oxygen  “aerobic”  enzymes O2O2 food ATP Make ATP! Make ATP! All I do all day… And no one even notices!

8. CO 2 + H 2 O + heat fuel (carbohydrates) O2O2 “Burn fuels” to make energy combustion making heat energy by burning fuels in one step ATP CO 2 + H 2 O + ATP (+ heat) respiration making ATP energy (& some heat) by burning fuels in many small steps food (carbohydrates) O2O2

9. Using ATP to do work? A working muscle recycles over 10 million ATPs per second Whoa! Pass me the glucose & oxygen! Can’t store ATP  too unstable  only used in cell that produces it  only short term energy storage  carbohydrates & fats are long term energy storage ATP ADP + P work

10. A Body’s Energy Budget eat food synthesis resting energy activity temperature control { growth reproduction { storage glycogen fat { ATP

11. What if oxygen is missing?  Can’t complete aerobic respiration  alcohol fermentation  yeast  glucose  ATP + CO 2 + alcohol  make beer, wine, bread  lactic acid fermentation  bacteria, animals  glucose  ATP + lactic acid  make yogurt  animals feel muscle fatigue O2O2 but only make a little bit of ATP!

12. 9-2 The Krebs Cycle and Electron Transport chain WHAT HAPPENS DURING THE KREBS CYCLE?  Pyruvic acid is broken down into carbon dioxide in a series of energy-extracting reactions  The Krebs Cycle takes place in the mitochondrial matrix  Most of the chemical energy gets transferred to electron carriers NAD+ and FAD+

13. HOW ARE THE HIGH-ENERGY ELECTRONS USED BY THE ELECTRON TRANSPORT CHAIN?  The electron transport chain uses high- energy electrons from the Krebs Cycle to convert ADP to ATP  This stage takes place in the inner mitochondrial membrane ATP

14. Any Questions??