5. Use of biological organisms

• What does fermentation mean?


  Anaerobic respiration in yeast and bacteria
• Why is yeast used to produce bread?

  it helps it rise by producing CO2
• Why is lactobacillus used to produce yogurt?


  -lactic acid causes milk proteins to denature

  -taste become more sour

  -texture is thicker
• Why do the conditions in an industrial fermenter need to be aseptic

  so that there are no pathogens to contaminate it
• Why does the level of nutrients in an industrial fermenter need to be controlled?

  so that there are enough nutrients for the microorganisms to grow
• Why does the temperature in an industrial fermenter need to be controlled

  so that the enzymes don't denature
• Why does the pH in an industrial fermenter need to be controlled

  so that the enzymes don't denature