Why does a plot of V vs S taper off and eventually reach a plateau at higher S
levels? - ANSWER - When S levels are high, the M-M plot approaches a
limiting value of Vmax.
- At high (S), where V approximates Vmax, virtually all of the enzyme active
sites are occupied by substrate.
- The addition of more S would not significantly increase the rate of reaction,
because the rate of reaction is limited by the total active sites available; once all
the sites are filled, the reaction can go no faster.
What is the Michaelis-Menten Equation? - ANSWER V = Vmax[S]/ [S] +km
The M-M Equation uses the terms (V), (Vmax), (S) and (Km). What do each of
these terms mean? - ANSWER V= observable velocity of the reaction. Tells us
how rapidly the reaction is forming product (p).
Vmax = fastest reaction rate possible under the given assay conditions. Has
dimensions of change in product concentration per unit time.
S = substrate concentration
Km = Michaelis Constant. Has units of concentration
What does the Km term tell us about an enzyme? - ANSWER The Km tells us
how efficient enzymes are at low substrate levels
What does it signify if an enzyme has a low Km or a high Km? - ANSWER -
The Km tells us how efficient enzymes are at low substrate levels?
- At low Km, the enzyme is very efficient at low substrate concentration. At
high Km, enzymes are inefficient at low substrate concentration.
What is the enzyme rate when the concentration of S = Km? - ANSWER 1/2
Vmax.
Why is a V vs S plot linear at low S concentrations? - ANSWER The M-M
equation reduces to V = K[S] which is the equation for a straight line.
levels? - ANSWER - When S levels are high, the M-M plot approaches a
limiting value of Vmax.
- At high (S), where V approximates Vmax, virtually all of the enzyme active
sites are occupied by substrate.
- The addition of more S would not significantly increase the rate of reaction,
because the rate of reaction is limited by the total active sites available; once all
the sites are filled, the reaction can go no faster.
What is the Michaelis-Menten Equation? - ANSWER V = Vmax[S]/ [S] +km
The M-M Equation uses the terms (V), (Vmax), (S) and (Km). What do each of
these terms mean? - ANSWER V= observable velocity of the reaction. Tells us
how rapidly the reaction is forming product (p).
Vmax = fastest reaction rate possible under the given assay conditions. Has
dimensions of change in product concentration per unit time.
S = substrate concentration
Km = Michaelis Constant. Has units of concentration
What does the Km term tell us about an enzyme? - ANSWER The Km tells us
how efficient enzymes are at low substrate levels
What does it signify if an enzyme has a low Km or a high Km? - ANSWER -
The Km tells us how efficient enzymes are at low substrate levels?
- At low Km, the enzyme is very efficient at low substrate concentration. At
high Km, enzymes are inefficient at low substrate concentration.
What is the enzyme rate when the concentration of S = Km? - ANSWER 1/2
Vmax.
Why is a V vs S plot linear at low S concentrations? - ANSWER The M-M
equation reduces to V = K[S] which is the equation for a straight line.
