Question

In Michaells-Menten kinetics, we assume steady-state kinetics. What does steady-state kinetics mean in this case? A) The concentration of the enzyme-substrate complex, [ES], is constant and does not change with time. B) The concentration of enzyme, [E] is fixed. C) The concentration of product, [P], is small and can be ignored. D) The concentration of substrate, [S], is much larger than the concentration of enzyme, [E],

Answer 1

Answer: Steady state of Kinetics in Michaelis-Menten equation means: A) the concentration of enzyme substrate complex is constant and does not change with time.

Explanation: Michaelis-Menten equation is an equation for enzymatic reactions,  E (enzyme)+ S(substrate) ↔ ES (enzyme substrate complex) ↔ E(enzyme) + P(Product). This equation is used to calculate the   $V_{\max }$ ie., the maximum rate of reaction at saturating substrate concentration. Michaelis constant ( $K_{{\mathrm {M}}}$ ) is the amount of substrate concentration where the reaction rate equals to half of $V_{\max }$ .

This works on the assumption that the concentration of ES does not change with time scale. Therefore, the rate at which ES is formed equals to the rate at which ES is used or the rate of formation of E-S is equal to the rate of breakdown of E-S. This is also known as Quasi-steady-state approximation.