Enzymes

Cards (29)

  • What do enzymes do to the rate of reaction?
    They increase the rate by lowering activation energy
  • What is the active site of an enzyme?
    Area where the reaction with substrate occurs
  • Why are enzymes specific to substrates?
    Only one type of substrate fits the active site
  • What happens when an enzyme and substrate form a complex?
    The enzyme's structure is altered to fit the substrate
  • What is the induced fit model?
    Enzyme structure changes to fit the substrate
  • What factors affect the rate of enzyme-controlled reactions?
    • Enzyme concentration
    • Substrate concentration
    • Temperature
  • How does enzyme concentration affect reaction rate?
    Increases rate until substrate becomes limiting factor
  • What happens when substrate concentration increases?
    Rate of reaction increases until enzyme becomes limiting
  • What is the optimum temperature for enzyme activity?
    Temperature at which enzymes work at maximum rate
  • What happens to the rate of reaction above the optimum temperature?
    Rate of reaction decreases
  • What is an inhibitor?
    A substance that slows down or stops a reaction
  • How do irreversible inhibitors affect enzymes?
    They permanently change the shape of the active site
  • What are examples of irreversible inhibitors?
    Heavy metal ions like mercury and cyanide
  • How do reversible inhibitors bind to enzymes?
    Through hydrogen bonds and weak ionic interactions
  • What are the two types of reversible inhibitors?
    Competitive and non-competitive inhibitors
  • How do competitive inhibitors affect enzyme activity?
    They compete with substrate for the active site
  • What happens to product formation with competitive inhibitors?
    Amount of product remains the same, rate decreases
  • How can the effect of competitive inhibitors be reversed?
    By increasing substrate concentration
  • How do non-competitive inhibitors affect enzyme activity?
    They change the shape of the active site
  • What are the three types of cofactors?
    • Coenzymes
    • Activators
    • Prosthetic groups
  • What role does Ritonavir play in HIV treatment?
    It inhibits HIV protease enzyme
  • What is an example of a drug that acts as an inhibitor?
    Penicillin inhibits transpeptidase enzyme
  • What is the effect of increasing substrate concentration on non-competitive inhibition?
    It has no effect on non-competitive inhibition
  • What are coenzymes?
    Organic cofactors that do not bind permanently
  • What is an example of a coenzyme?
    NAD derived from niacin
  • What are activators?
    Inorganic metal ions that temporarily bind to enzymes
  • What is an example of an activator?
    Magnesium ion
  • What are prosthetic groups?
    Permanently attached groups to enzymes
  • What is an example of a prosthetic group?
    Haem group in hemoglobin