Enzymes

• Enzymes are proteins that are involved in all metabolic reactions, they function as biological catalysts.
• Each enzyme has an active site that has a complementary shape to its substrate.
• The properties of enzymes:

  1. All enzymes are protein
  2. Enzymes are made inactive by high temperatures
  3. Enzymes work best at optimum temperature and pH
  4. Enzymes are catalysts
  5. Enzymes are specific
• Cells create enzymes based on instructions carried in the cells' genes.
• Enzymes speed up reactions by lowering the activation energy.
• The activation energy is needed to start a reaction
• Enzymes are protein molecules and made up of amnio acids.
• Denature is the state of an enzyme when it loses its shape or has been irreversibly damaged.
• Intracellular enzymes are enzymes that works inside the cells
• Extracellular cells are enzymes that are made inside the cell and then released from the cell
• Factors that affect the rate of reaction:

  • Temperature
  • pH
  • Surface Area
  • Pressure
  • Enzyme Concentration
  • Substrate concentration
• Anabolic reactions: Build up large molecules from smaller molecules and usually requires energy.
• Catabolic reactions: break down large molecules into smaller molecules, and often release energy
• Catalase: an enzyme that catalyzes the breaks down of hydrogen peroxide into water and oxygen
• Catalyst: a substance that increases the rate of a chemical reaction and is not changed.
• Catalyse: to make a chemical reaction happen more quickly
• Pectinase: group of enzymes that breaks down pectin.
• Trypsin: proteolytic enzyme secreted in pancreatic juice and breaks down proteins into amino acids..
• Pepsin: digestive enzyme in stomach, breaks down protein into polypeptides.
• Substrate: the substance that an enzyme causes to react.
• Active site: The part of an enzyme molecule to which the substrate temporarily binds
• Biuret test would give a positive result for testing a solution containing only enzyme.
• A reaction controlled by an enzyme happens more slowly as temperature decreases because the enzyme and substrate molecules have less kinetic energy.
• The smaller molecules from which an enzyme molecule is made are amino acids.
• Pepsin + protein = polypeptides
• Catalase + Hydrogen peroxide = water + oxygen
• Protease + proteins = amino acids
• Lipases + Fats n oils = Fatty acids + glycerol
• Amylase + Starch = Maltose
• Maltase + Maltose = Glucose