Cellular Respiration

• Cellular Respiration – mitochondria break down food molecules to produce ATP

• 3 stages

Glycolysis

Citric Acid Cycle (Kreb’s Cycle)

Electron Transport Chain

Glycolysis

• 2 molecules of ATP needed- 4 produced for net gain of 2 ATP

• series of chemical rxn’s that break down glucose 2 molecules of pyruvic acid

C-C-C-C-C-C C-C-C + C-C-C

• Pyruvic acid then moves into the mitochondria

• Aerobic or Anaerobic Respiration

Anaerobic: Fermentation

• Lactic Acid Fermentation

• Alcoholic Fermentation

Lactic Acid Fermentation

• Occurs in muscle cells during strenuous exercise

• Form 2 molecules of lactic acid• lactic acid accumulates in the cells

increasing the acidity and causing muscle fatigue

• Lactic acid travels to liver and is converted back to pyruvic acid

Alcoholic Fermentation

• Used by yeast cells and some bacteria to produce CO2 and ethyl alcohol

• CO2 forms bubbles in the dough when making bread

• basis of the wine and beer industry

Aerobic Respiration

• Krebs Cycle

1. occurs in the mitochondria

2. each turn of the cycle produces 2 molecule of ATP & 2 molecules of CO2

• Electron Transport Chain

1. takes place on the cristae

2. O2 + 4e- + 4H+ 2 H2O + 32 ATP

Summarizing Cellular Respiration

• C6H12O6 + 6O2 6CO2 + 6H2O + energy

• Products of photosynthesis are the reactants in cellular respiration

• Aerobic respiration is not the reverse