3.4.1.1 Microorganisms and Enzymes

• Microorganisms are microscopic living entities like bacteria, yeasts, moulds, and viruses
• What are microorganisms involved in food spoilage?

  Bacteria, yeasts, moulds, viruses
• Bacteria are single-celled organisms that reproduce rapidly.
• Which bacteria commonly cause food poisoning?

  Salmonella, E. coli
• Yeasts are single-celled fungi that reproduce through budding
• What is the role of moulds in food spoilage?

  Produce toxins on food
• Which viruses are commonly involved in food contamination?

  Norovirus, Hepatitis A
• Match the microorganism type with its role in food spoilage:

  Bacteria ↔️ Toxin production, food poisoning

  Yeasts ↔️ Fermentation, off-flavours

  Moulds ↔️ Visible spoilage, toxin production

  Viruses ↔️ Cause illness through contamination
• Bacteria are single-celled organisms that reproduce rapidly
• Which enzyme reaction can cause browning in cut apples?

  Oxidation
• Microorganisms contribute significantly to food spoilage and contamination.
• Match the microorganism type with its characteristics:

  Bacteria ↔️ Single-celled, fast reproduction

  Yeasts ↔️ Single-celled fungi

  Moulds ↔️ Multi-celled fungi

  Viruses ↔️ Require host cells to reproduce
• What is the role of moulds in food spoilage?

  Toxin production, visible spoilage
• Enzymes are biological catalysts that speed up chemical reactions in food
• Oxidation is an enzymatic reaction that can alter the taste and color of food.
• Which foods are commonly affected by oxidation reactions?

  Fruits, fats
• Oxidation reacts with oxygen to alter the taste and color
• Hydrolysis involves the breaking of chemical bonds using water.
• Enzymes are biological catalysts
• Ripening involves the breakdown of complex molecules in fruits and vegetables.
• What chemical change causes browning in cut apples?

  Enzymatic reactions
• Enzymes, unlike microorganisms, are not living and do not multiply
• Microorganisms and enzymes both require specific conditions to thrive in food.
• Match the microorganism type with its characteristics:

  Bacteria ↔️ Single-celled, rapid reproduction

  Yeasts ↔️ Single-celled fungi

  Moulds ↔️ Multi-celled fungi

  Viruses ↔️ Require host cells
• Yeasts cause fermentation and off-flavours
• What effect do moulds have on food spoilage?

  Produce toxins
• Cooling slows microbial growth and enzymatic activity