Biological Catalysts: Enzymes and Their Functions

Biological Catalysts

• Enzymes are biological catalysts that speed up chemical reactions without being consumed or changing the product.
• Enzymes are proteins involved in all metabolic reactions.
• The substance an enzyme acts upon is called a substrate.
• Each enzyme has a specific substrate it works on.

Characteristics of Enzymes

• Specificity: Each enzyme catalyzes a specific reaction.
• Temperature Sensitivity: Enzyme activity increases with temperature until an optimal point (around 35°C–40°C).
• pH Sensitivity: Enzyme activity is optimal at a specific pH, with deviations reducing activity.
• Denaturation: Extreme temperatures or pH values can denature enzymes, rendering them inactive.

Enzyme Function

• Active Site: Enzymes have a specific region called the active site where the substrate binds.

Role of Enzymes in Germination

• Seeds contain stored insoluble food with inactive enzymes.
• When water enters a seed in favorable conditions, enzymes become active and break down stored insoluble food into soluble forms.
• The soluble food nourishes the embryo until it develops green leaves for photosynthesis.
• Key enzymes in germination:
  • Amylase: Breaks down starch into maltose.
  • Proteases: Break down proteins into amino acids.

Role of Enzymes in Biological Washing Powder

• Biological washing powders contain enzymes that break down stain molecules into soluble forms, allowing them to be washed away.
• Key enzymes in washing powders:
  • Lipases: Break down fats into fatty acids and glycerol, removing greasy stains.
  • Proteases: Break down proteins into amino acids, removing protein stains like blood.

Advantages of Biological Washing Powder

• Economical: No need for boiling, saving energy.
• Gentle on Clothes: Avoids damage caused by boiling and rubbing.

Precautions for Biological Washing Powder

• Not suitable for silk, wool, or leather since they are protein-based and can be damaged by proteases.
• Wash hands after using biological washing powders to avoid enzyme exposure.

Role of Enzymes in the Food Industry

• Pectinase is used in juice making:
  • Pectinase acts on pectin, a substance found in plant cell walls.
  • Benefits of pectinase in juice production:
    • Easier to squeeze juice from fruit.
    • Increases juice volume.
    • Makes juice clearer.

Role of Enzymes in Making Baby Food

• Proteases are used in making baby foods:
  • Break down proteins into smaller polypeptides or amino acids, facilitating digestion.
• Amylase is used to obtain sugar from starch:
  • Produces maltose for sweetening purposes.
• Isomerase converts glucose into fructose:
  • Fructose is sweeter than glucose, allowing for reduced sugar content in products for diabetics.
• Lactase breaks down lactose in milk:
  • Helps individuals with lactose intolerance digest milk.
• Rennin clots milk in the initial stage of cheese making.

Advantages of using Enzymes in Industry

• Energy Efficiency: Enzymes work at low temperatures, saving energy.
• Corrosion Resistance: Enzymes are not corrosive.
• Specificity: Enzymes work on specific substrates, allowing for controlled processes.