B3.4 Catalysts & enzymes

• What is a catalyst?

  A catalyst is a substance that speeds up a chemical reaction without being used up.
• How do enzymes function as biological catalysts?

  Enzymes speed up reactions in the body by interacting with specific substrates.
• What does metabolism involve?

  Metabolism involves the sum of all chemical reactions in a cell or in the body.
• How do you control the rate of chemical reactions when cooking?

  You control the rate by altering the temperature.
• What happens to a catalyst during a chemical reaction?

  A catalyst is not used up and can be used repeatedly.
• What are enzymes made of?

  Enzymes are made of a combination of amino acids.
• Why is the shape of an enzyme important?

  The shape of an enzyme is vital because it determines its specificity for a substrate.
• What is the lock and key theory in relation to enzymes?

  The lock and key theory describes how an enzyme and substrate fit together specifically for a reaction.
• What is the active site of an enzyme?

  The active site is the specific region where the substrate binds to the enzyme.
• How do enzymes control metabolism?

  Enzymes control metabolism by catalyzing specific reactions without interfering with others.
• What is an example of a reaction that enzymes can catalyze?

  Building proteins from amino acids is an example of a reaction catalyzed by enzymes.
• What is another example of a reaction that enzymes can catalyze?

  Breaking down carbohydrates into simpler sugars is another example of an enzyme-catalyzed reaction.
• What is hydrogen peroxide in the context of cellular reactions?

  Hydrogen peroxide is a poisonous waste product of reactions in a cell.
• Why is it important to break down hydrogen peroxide quickly?

  It is important to break down hydrogen peroxide quickly to prevent damage to cells.
• How can you measure the rate of reaction when breaking down hydrogen peroxide?

  You can measure the volume of oxygen produced over time.
• What safety precautions should be taken when working with hydrogen peroxide?

  Use eye protection and handle hydrogen peroxide as it is an irritant.
• What are the key points about catalysts and enzymes?

  • Catalysts increase the rate of chemical reactions without changing chemically themselves.
  • Enzymes are biological catalysts that change specific reactions in living organisms due to the shape of their active site.
  • Enzymes are proteins made of amino acid chains folded into specific shapes.
  • Metabolism is the sum of all reactions in a cell or body.
• What happens to the rate of reaction when using manganese(IV) oxide compared to hydrogen peroxide alone?

  The reaction occurs much faster with manganese(IV) oxide than with hydrogen peroxide alone.
• What is an example of an enzyme produced by living organisms that is present in the air we breathe?

  Catalase is an example of an enzyme produced by living organisms.
• What is the significance of the shape of the active site in enzyme function?

  The shape of the active site allows the enzyme to bind specifically to its substrate.
• How do enzymes ensure that reactions in cells do not interfere with each other?

  Each enzyme catalyzes a specific reaction, ensuring control and efficiency in cellular processes.