A Michaelis-Menten plot is a graph that describes how the concentration of the substrate affects the rate of the reaction. As the substrate concentration increases, the rate of the reaction also tends to increase.
Michaelis-Menten kinetics describe the velocity of a reaction involving an enzyme and a substrate. The enzyme and the substrate bind together to form a complex in a reversible reaction. This complex can either dissociate to give back the enzyme and substrate, or could move forward to give the enzyme and a product.
The Michaelis-Menten plot describes how the concentration of the substrate can push the reversible enzyme-substrate reaction either forward or backwards. As the concentration of the substrate is increased, the rate of the forward reaction increases only until it reaches its maximum velocity (Vmax). The resulting curve of the plot shows a steady increase in reaction rate with increase in substrate concentration followed by gradual plateauing of the curve at Vmax.
The plot is also used to determine the constant, Km, of a reaction, which is the concentration of the substrate when the reaction rate is only half of Vmax. The Km is used to determine the velocity of the reaction using the Michaelis-Menten equation, which is given as v = [(Vmax * concentration of the substrate)/(Km + concentration of the substrate)].