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