enzymes

• What is metabolism?

  All chemical reactions in an organism.
• What are the two main types of metabolic processes?

  • Anabolic: Smaller molecules build up to form larger molecules (e.g., photosynthesis, protein synthesis, DNA replication).
  • Catabolic: Breakdown of larger molecules into smaller molecules (e.g., respiration, digestion).
• What is the function of enzymes?

  Enzymes are biological catalysts.
• What is the composition of enzymes?

  Enzymes are composed of proteins.
• Where are enzymes produced?

  Enzymes are produced by ribosomes.
• What is the shape of enzymes?

  Enzymes are 3-D folded shaped.
• What factors are enzymes very specific to?

  Enzymes are very specific to temperature and pH.
• What is the Induced Fit Theory of enzyme action?

  1. Complementary shape to substrate.
  2. Active site induces to accommodate substrate forming enzyme-substrate complex.
  3. Product is produced and enzyme returns to original shape to be reused.
• What is a substrate in enzyme reactions?

  The substance with which an enzyme reacts.
• What is a product in enzyme reactions?

  The substance the enzyme forms.
• What is the active site of an enzyme?

  The part of an enzyme that combines with the substrate.
• What is the enzyme-substrate complex?

  Enzyme + substrate together.
• What does enzyme specificity mean?

  Enzymes only act on one substrate due to the active site.
• What is the pH at which amylase acts?

  pH 7.
• What is the pH at which pepsin acts?

  pH 2.
• What happens to an enzyme when it goes outside of its optimum pH or temperature?

  It starts to become denatured and activity is reduced or doesn’t occur at all.
• What is a denatured enzyme?

  A denatured enzyme has lost its shape and can no longer carry out its function.
• What is enzyme immobilisation?

  • Enzymes that are fixed.
  • Used in bio-processing to produce products like medicines, yogurts, and beers.
• What is a bioreactor?

  A vessel/container in which living cells or their products are used to make a product.
• What are the advantages of immobilised enzymes?

  1. They can be reused, making them less wasteful and cost-effective.
  2. The product can be purified easily due to enzymes being easily recovered.
• What immobilised enzyme is used to make fructose in soft drinks?

  Glucose isomerase.
• Name two catabolic enzymes.

  • Amylase
  • Lipase
  • Pepsin
• Name one anabolic enzyme.

  • Polymerase
• What are the physical and chemical methods of immobilising enzymes?

  Physical methods:

  • Trapped in a gel (e.g., sodium alginate)

  
  

  Chemical methods:

  • Bonded to a support
• Explain enzyme specificity with reference to the active site.

  Only one substrate fits the shape of the active site, which changes shape to form an enzyme-substrate complex.
• What happens to enzyme activity when placed in a medium outside of their optimum pH?

  Enzyme activity is reduced due to its shape changing or becoming denatured.
• Name two substances used to immobilise enzymes or yeast cells in a lab.

  Sodium alginate and calcium chloride.
• What are two advantages of using immobilised enzymes?

  1. Enzyme and product can be easily separated.
  2. Enzymes can be recycled a lot easier.
• Name two factors that affect enzyme activity.

  pH and temperature.
• What is the substrate of the catalase enzyme used in school experiments?

  Hydrogen peroxide.
• What are the products of the catalase enzyme used in school experiments?

  Oxygen gas and water.
• How is the rate of enzyme activity measured?

  Using a stopwatch and the volume of bubbles produced per minute.
• What is the purpose of a pH buffer when investigating the effect of temperature on enzyme activity?

  To keep the pH constant.
• Name two processes that occur in plants or animal cells that require enzymes.

  • Respiration
  • Photosynthesis
• Explain optimum activity in relation to enzymes.

  Optimum activity is the best pH or temperature range for the enzyme to maximize its rate of activity.
• What is the chemical nature of enzymes?

  Enzymes are proteins.
• What is the molecular shape of enzymes?

  Enzymes are folded into a 3D shape.
• Why is it necessary to keep pH constant when testing temperature on the effect of enzyme activity?

  To ensure only one variable (temperature) is tested.
• What are two features of a denatured enzyme?

  • Lack of shape
  • Doesn’t work
• Name the four elements always found in enzymes.

  • Carbon
  • Oxygen
  • Hydrogen
  • Nitrogen