Cell Respiration
How do we get energy from food?
Cell Respiration – mitochondria break down
food to make ATP (energy)
Formula:
C6H12O6 + 6O2 -----> 6CO2 + 6H20 + energy (heat and ATP)
1 glucose + 6 oxygen  6 carbon dioxide + 6 water + energy
3 Stages of Cell Respiration
1.
2.
3.
3 Stages of Cell Respiration:
1. Glycolysis
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•
•
•
Anaerobic – no oxygen required
Occurs in the cytoplasm
Glucose  2 pyruvic acids*
Net ATP production = 2
3 Stages of Cell Respiration:
2. Citric Acid Cycle (a.k.a. Krebs Cycle)
• Occurs in mitochondria, requires oxygen
(aerobic)
• Net ATP production = 2
3 Stages of Cell Respiration:
3. Electron Transport Chain
• Occurs in mitochondria, requires oxygen
(aerobic)
• Net ATP = 32
Electron Transport Chain Animation
* If oxygen is not available, cell undergoes
fermentation after glycolysis.
2 Types of Fermentation
2 Types of Fermentation:
1. Lactic Acid – lactic acid builds up in
muscles when they do no get enough
oxygen  muscle fatigue
Other Products?
2 Types of Fermentation:
2. Alcoholic – yeast cells produce CO2 and
ethyl alcohol (a.k.a. ethanol).
Other Products?
Aerobic vs. Anaerobic
AEROBIC
CONDITIONS:
ANAEROBIC
CONDITIONS:
(oxygen present)
(no oxygen)
Cell Respiration
36 ATP
Fermentation
2 ATP
Which is more efficient (which produces MORE energy)?