Required Practical 1

• What bond holds beta glucose molecules together in cellulose?

  Glycosidic
• Which bonds form during the secondary structure of proteins?

  Hydrogen
• What is an enzyme?

  A biological catalyst speeding up reactions
• How does the lock and key theory differ from the induced fit model?

  Lock and key fits exact; induced fit changes shape
• How do non-competitive inhibitors affect enzymatic reaction rate?

  They lower end product by changing enzyme shape
• What is the effect of temperature on enzyme reaction rate?

  • Lower temperature: lower kinetic energy, slower reactions
  • Higher temperature: can lead to denaturation
• What are the steps to follow for the enzyme practical investigation?

  1. Write a risk assessment
  2. Draw a table of results
  3. Draw a graph with labeled axes
  4. Write a conclusion explaining results
  5. Write an evaluation discussing reliability
• What is casein?

  A protein found in milk
• What happens when trypsin is added to milk powder?

  The casein is digested, and solution clears
• What is the method for measuring the effect of temperature on trypsin activity?

  Time how long it takes for 'X' to clear
• What should be done if there is no clearing within 20 minutes?

  Consider the time as infinity
• What is a risk assessment?

  Evaluating potential risks and solutions
• How can risks be minimized in the enzyme practical?

  By following safety procedures and guidelines
• How do you calculate the rate of reaction at each temperature?

  Divide 1000 units by time in seconds
• What does a mean reaction rate indicate?

  The average rate of reaction across trials
• What should be done if results are not precise?

  Identify anomalies and suggest improvements
• What shape does the graph of enzyme reaction rate against temperature typically show?

  A bell-shaped curve
• What is the Q10 of an enzyme reaction if it is 15 units at 40 °C and 6 units at 50 °C?

  Q10 = $\frac{15}{6} =$$2.5$
• What describes the shape of the curve for mammalian enzymes between 10 °C and 35 °C?

  A positive, increasing gradient
• What are the key components of the enzyme practical investigation?

  • Temperature variations (20 °C to 60 °C)
  • Trypsin and milk powder as reactants
  • Measuring time for clearing
  • Risk assessment and safety measures