• author "Joshua Ellis"
    • tags "HUCM"
    • description ""
    • fileName "Enzymes"
    • freezingBlueDBID -1.0
    • What is the Michaelis -Menten Equation

    Vo= Vmax[S]/(Km+[S]
  1. Vo= initial velocity
    • Vmax= maximal velocity
    • Km= Michaelis constant = (k-1 + k2)/k1
    • [S]=substrate concentration
  2. What is Km? Relate it to Vmax.
    • Michaelis constant
    • (k-1 +k2)/k1 (all the rate constants below)

    • k1 k2
    • E+S <---> ES ---> E+P
    • k-1
    • Does not change with concentration of enzyme. Basically equal to reaction velocity = 1/2 Vmax
  3. What does a low and high Michaelis constant mean?
    • Small Km = high affinity of the enzyme for substrate. (low concentration of substrate need to half saturate the enzyme--reach v=1/2vmax)
    • Large Km = low affinity. Cuz a high concentration is required.
  4. What is the relationship to enzyme concentration and velocity of reaction?
    ALWAYS directly proportional. If you half [E] then the Vo and Vmax will also be halved
  5. How can you determine the order of the reaction?
    • When [S] is much less than Km velocity is proportional to [S]-----FIRST ORDER
    • When [S] is much greater than Km velocity is constant and equal to Vmax (independent of [S])----- ZERO ORDER
  6. How do you make the Lineweaver-Burke Plot? What does it tell you? What is the equation?
    Its the reciprocal of the Michaelis Menten equation

    It can tell you the Km and Vmax (as x and y intercepts)

    1/vo= Km/(Vmax[S]) + 1/Vmax
  7. Reversible inhibitors have what type of bond?
  8. What is competitive inhibition? What is the effects on Vmax, Km, and Lineweaver Burke Plot
    Binds to active site

    • Vmax is the same
    • Increased Km because need more [S]
    • Graph y intersect is same but x intercept is increased (obvious slope change)
  9. What is non-competitive inhibition? What is the effects on Vmax, Km, and Lineweaver Burke Plot
    non active site binding

    • Vmax decreased
    • Km is the same

    The graph x intercept is the same
Card Set
enzymes from book