Enzymes and biological reactions

• What is the protein nature of enzymes?


  Enzymes are proteins that act as biological catalysts.
• What are the general properties of enzymes?


  • Enzymes are specific to substrates
  • They lower activation energy
  • They are not consumed in reactions
  • They can be regulated by inhibitors
• Where do enzymes typically act?


  Enzymes act at specific sites known as active sites.
• What is the lock-and-key model of enzyme action?


  The lock-and-key model describes how a substrate fits into an enzyme's active site like a key fits into a lock.
• What is lysozyme and its role in enzyme action?


  Lysozyme is an enzyme that breaks down bacterial cell walls, demonstrating enzyme specificity.
• How do enzymes affect activation energy?


  Enzymes lower the activation energy required for a reaction to occur.
• What is the course of an enzyme-controlled reaction?


  1. Substrate binds to the active site
  2. Enzyme-substrate complex forms
  3. Reaction occurs, producing products
  4. Products are released, and enzyme is free to catalyze another reaction
• What factors affect enzyme activity?

  Factors include temperature, pH, enzyme concentration, and substrate concentration.
• How does temperature affect enzyme activity?


  Temperature affects enzyme activity by influencing the rate of molecular collisions and enzyme stability.
• How does pH affect enzyme activity?


  pH affects enzyme activity by altering the enzyme's shape and charge, impacting substrate binding.
• What is enzyme concentration's effect on enzyme activity?


  Increasing enzyme concentration generally increases the rate of reaction, assuming substrate is available.
• What is enzyme inhibition?


  • Enzyme inhibition is the process where a molecule reduces or stops enzyme activity.
  • Types include competitive and non-competitive inhibition.
• What is non-competitive inhibition?


  Non-competitive inhibition occurs when an inhibitor binds to an enzyme at a site other than the active site, reducing its activity.
• What are immobilised enzymes?


  • Enzymes that are attached to an inert support
  • Used to enhance stability and reusability
  • Commonly used in industrial processes
• What are enzymes primarily composed of?


  Globular proteins
• How are enzymes synthesized?


  They are synthesized by living cells
• What are the two types of enzymes based on their location of action?


  Intercellular enzymes and extracellular enzymes
• What is the role of the active site in an enzyme?


  It is the 3D space where specific substrate molecules can fit and bind
• How does the sequence of amino acids affect the enzyme's function?


  A change in the sequence alters the shape of the active site, preventing substrate binding
• What happens when a substrate binds to an enzyme's active site?


  • The substrate fits into the active site
  • An enzyme-substrate complex is formed
  • Interactions occur between the substrate and amino acid groups
• What factors affect the ability of R groups and substrates to form bonds?


  Temperature and pH
• What happens to the bonds in the substrate when they are distorted?


  It puts a strain on the bonds, increasing the chance they will break
• What occurs after the bonds in the substrate are broken?


  New atoms in the substrate come closer together, allowing new bonds to form
• What is the energy required to break existing bonds called?

  Activation energy
• How do enzymes affect the activation energy of a reaction?


  They reduce the activation energy needed for the reaction to take place
• What is the role of enzymes in biological reactions?


  They act as biological catalysts to speed up reactions
• What is the nature of enzymes?

  Enzymes are proteins.
• What are the sites of enzyme action?

  • Active sites
  • Lock-and-key model
  • Induced fit model
• What are the general properties of enzymes?

  Enzymes are specific, efficient, and can be regulated.
• What is an active site?

  The active site is the region on an enzyme where substrate molecules bind.
• What does the lock-and-key model describe?

  The lock-and-key model describes how substrates fit into the active site of an enzyme.
• What is lysozyme's role in the induced fit model?

  Lysozyme demonstrates the induced fit model by changing shape to better fit the substrate.
• How do enzymes affect activation energy?

  Enzymes lower the activation energy required for a reaction to occur.
• What is the course of an enzyme-controlled reaction?

  1. Substrate binds to the active site.
  2. Enzyme-substrate complex forms.
  3. Reaction occurs, producing products.
  4. Products are released, and the enzyme is free to catalyze another reaction.
• What are the factors affecting enzyme activity?

  Temperature, pH, substrate concentration, and enzyme concentration
• How does temperature affect the rate of enzyme action?

  Increased temperature generally increases the rate of enzyme action up to a certain point
• What is the effect of pH on enzyme activity?

  Each enzyme has an optimal pH at which it functions best
• How does substrate concentration influence enzyme activity?

  Increasing substrate concentration increases the rate of reaction until a maximum rate is reached
• What happens to the rate of enzyme reaction once a product is formed?

  The rate of the enzyme reaction slows down
• What is the substrate in the context of enzyme activity?

  A substrate is the substance on which an enzyme acts