Computing Kcat by hand. If you plot enzyme velocity as a function of subtrate concentration, you can fit the data to the Michaelis-Menten equation to determine the K m and V max. The V max is the maximum enzyme velocity extrapolated out to very high concentrations of substrate.

Kcat是转换量-单位时间内每个酶位点转化为产物的底物分子数。 如果知道酶位点的浓度，则在分析底物对速度曲线时，可使用Kcat代替Vmax。 模型

Vmax & Kcat. Figure 5.2.1: plot of Velocity vs Substrate Concentration ( V vs. [S]). On a plot of initial velocity vs Substrate Concentration ( v vs. [S]), the maximum velocity (known as Vmax) is the value on the Y axis that the curve asymptotically approaches.

Kcat/Km就可以用来确定酶的最适底物，同一个酶对不同底物的Kcat/Km最大可相差100万倍。 当利用蛋白质工程对酶进行改造时，不同突变型的Kcat/Km也是需要测定的参数，用来表征酶催化效率的变化情况。

Kcat is the turnover number -- the number of substrate molecule each enzyme site converts to product per unit time. If you know the concentration of enzyme sites, you can fit Kcat instead of Vmax when analyzing a substrate vs. velocity curve.

Kcat是用Vmax算出来的，而Vmax显然是外推得到的。 而米氏方程完成的条件是在测定过程中底物浓度变化不大，在底物浓度太低时，由于底物的量少，变化率可能较大加上系统的波动（导致不准）而底物浓度太高，速度太快，导致初速度测不准。

Notice \(k_2\) describes an irreversible reaction as opposed to an equilibrium expression, when compared to k-1 and k1. k2 here is also known as kcat, the catalytic efficiency of enzyme. From the previous discussion, v0 is the measured reaction rate, which is the product formation over time, so it can be concluded that an equation would look ...

2025年3月12日 · Define and interpret the kinetic parameters KMK_M (Michaelis constant), VmaxV_ {max} (maximum velocity), and kcatk_ {cat} (turnover number), including their units and physical significance. Explain how initial rate (v₀) measurements are obtained from progress curves and how these data are used to generate hyperbolic vv vs. [S] plots.

2024年10月1日 · Questions about enzyme’s kinetics often involve interpreting graphs, calculating Km and Vmax, and understanding the effects of inhibitors on enzyme activity. Tips for Enzyme Kinetics on the MCAT. Familiarize yourself with the Michaelis-Menten and Lineweaver-Burk plots. Understand how competitive and non-competitive inhibitors affect Vmax and Km.

2021年6月11日 · Write an equation to represent kcat at this concentration. Draw a graph of v (rate) vs [S] for a saturated enzyme. If the enzyme system is not under saturation conditions, then diffusion (and binding) may play a bigger role. If enzyme is saturated, k cat is more important. Draw reaction progress diagrams for these two scenarios. each.