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是酶的催化常数，定义为在单位时间内每一活性中心或每分子酶所能转换的底物 分子数，表示酶催化特定底物的能力。 其单位一般是s-1，即每秒钟内一个酶分子或酶活性中心能催化多少个底物发生反应。

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1月21日 · The Lineweaver–Burk plot was widely used to determine important terms in enzyme kinetics, such as \(K_m\) and \(V_{max}\), before the wide availability of powerful computers and non-linear regression software. The y-intercept of such a graph is equivalent to the inverse of \(V_{max}\); the x-intercept of the graph represents \(−1/K_m\).

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.

2024年8月31日 · To gain a deeper understanding of enzyme kinetics, the study of how enzymes perform their remarkable catalytic functions, we need to introduce a powerful tool: the Lineweaver-Burk plot, a graphical representation of the Michaelis-Menten equation. Constructing a Lineweaver-Burk Plot.