Chapter 7 // Pt3: Anaerobic Cellular Respiration

Anaerobic Cellular Respiration

Fermentation

• Anaerobic
• Found in nearly all cells (plants, animal, bacteria)
• Used alongside aerobic cell respiration in most cells
• Different types of fermentation variations depending on cells
• Happens in the cytoplasm
• Essentially just: glycolysis plus an extra step (NAD+ regeneration)
• Doesn’t completely break down glucose like aerobic resp.
• Doesn’t use oxygen = less dangerous ( less risk of free radicals)

ATP Production

• Only produces 2 molecules of ATP thru glycolysis
  • Not sustainable for most cells
• Aerobic respiration produces 36 molecules of ATP

Two Types

• The product defines the type

Alcoholic Fermentation

• Converts glucose into ethyl alcohol
  • AKA ethanol

1. Glycolysis runs. Produces: 2 ATP, 2 NADH, 2 pyruvates
2. Pyruvate loses carbon as CO₂, remaining fragment of pyruvate = acetaldehyde
3. Acetaldehyde accepts H+ and electrons from NADH = ethanol

Uses: food (bread, wine, beer, vinegar), medicines (antiseptics, disinfectants), biofuels

Lactate Fermentation

• Converts glucose into lactate
  • AKA lactic acid fermentation

1. Glycolysis runs. Produces: 2 ATP, 2 NADH, 2 pyruvates
2. NADH donates electrons and H+ to pyruvate = lactate

• Nothing is being broken down, no C lost= no CO₂ produced
• Uses: cheese,yogurts, kimchi, pickles. Soy sauce, miso paste, sausage, bacon (curing meats)
• Also used in animal skeletal muscles

Intense exercise depletes O₂ in muscles, anaerobic fermentation takes over and makes small amounts of ATP. For quick bursts of activity, doesn’t support prolonged exertion since little ATP us made