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 • • • • 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)?