Name: graphing enzyme kinetics data
Uploaded: 2023-04-30T10:09:42.000Z
Duration: 1 min 19 s
Channel: JoVE

K12 Standards

north-carolina-k-12-science-standard-course-of-study

North Carolina K-12 Science Standard Course of Study

9-12

Biology

from-molecules-to-organisms-structures-and-processes

From Molecules to Organisms- Structures and Processes

LS.Bio.1.2

Introduction to Enzyme Kinetics

酶动力学研究酶催化反应的速率。通过测量不同底物浓度下重复实验中底物消耗或产物生成随时间的变化，来监测反应速率。
这些结果可以绘制成图表，以显示底物浓度如何影响反应的速率或速度。
在低浓度下，反应速度随着底物量的增加而线性增加，但在较高浓度下开始趋于平缓。反应速率达到一个最大值，即Vmax——此时酶被底物完全饱和时的反应速率。
酶亲和力用于衡量酶与其底物结合的强弱程度，通常以米氏常数KM来量化。当反应速率达到最大速率Vmax的50%时，对应的底物浓度即为KM的数值。
一个小的 KM 表示一种酶具有较高的底物亲和力 反之亦然一种分子量较大的酶 KM 与具有较低底物亲和力的酶相比，需要更高的底物浓度才能接近其最大反应速度 KM.

<ol>
	<li>Voet D. 和 Voet J.G. 生物化学，第 4 版。 John Wiley & Sons，2010 年，第 487-492 页</li>
	<li>Berg J.M.、Tymoczko J.L. 和 Stryer L. 生物化学，第 5 版，W.H. Freeman and Co.，第 8.4 节</li>
</ol>

酶动力学简介

酶动力学能够用来研究生化反应的速率。科学家们会监测特定的酶促反应在不同底物浓度下的反应速率。同时还可以使用抑制剂或影响反应速率的其他分子来进行额外的试验。

然后，实验人员可以将给定试验的初始反应速率或速度（Vo）与底物浓度（[S]）来进行对比，从而能够得到反应特性图。对于许多有关单一底物的酶促反应来说，这些数据符合米氏（Michaelis-Menten）方程，该方程是由米凯利斯（Leonor Michaelis）和莫德·门滕（Maud Menten）来进行推导的。

<img alt="Eq1" src="/files/ftp_upload/12164/12164_Equation 1.png" style="text-align: center; height: 70px;" />

该方程估计了所研究酶的最大速度（Vmax）和米氏常数（KM），并且会基于以下假设：

<ol>
	<li>在反应开始时没有产物。</li>
	<li>酶-底物复合物形成的速率等于将其解离和分解为产物的速率。</li>
	<li>与底物的浓度相比，酶的浓度是最小的。</li>
	<li>仅测量初始反应速率。</li>
	<li>该酶能够以游离的形式或以酶-底物复合物的形式存在。</li>
</ol>

对米氏方程进行不同的重新排列，例如Lineweaver-Burke（双倒数）图、Eadie-Hofsteot 图和 Hanes-Woolf 图，这些都是绘制动力学参数图的替代方法。双倒数图通常用来估计米氏常数和最大速度。该图使用了米氏方程图中 x 轴和 y 轴的倒数值。从数学上来讲，y 轴的截距等于 1/Vmax，x 轴的截距则等于 -1/KM。

双倒数图能够用来直观地区分抑制剂类型 —— 竞争性抑制剂、非竞争性抑制剂和反竞争性抑制剂。对米氏方程采用不同的重新排列方式（例如 Eadie-Hofstee 和 Hanes-Woolf 图）也能够用来确定动力学参数。

酶动力学研究生化反应的反应速率。科学家在不同底物浓度下监测特定酶促反应的反应速率，……

Education

教育

JoVE Core

Cell Biology

细胞生物学

Unit 1

第一单元

Energy and Catalysis

能量与催化

KEY TERMS AND CONCEPTS

关键术语与概念

graphing enzyme kinetics data

Enzyme kinetics uses graphs to show how fast a biochemical reaction happens. Scientists measure the initial reaction rate, or velocity (Vo), at different substrate concentrations ([S]). They may also run trials with inhibitors or other molecules that change the reaction rate.

The results are often plotted as Vo against [S]. For many single-substrate reactions, the data fits the Michaelis-Menten equation. This equation, named after Leonor Michaelis and Maud Menten, helps estimate the maximum velocity (Vmax) and the Michaelis constant (KM) for the enzyme being studied.

The Michaelis-Menten model is based on a few assumptions. No product is present at the start of the reaction. The rate of enzyme-substrate complex formation equals the rate of its breakdown into products and its dissociation. The enzyme concentration is minimal compared with the substrate concentration. The model also uses only the initial reaction rates. In this setup, the enzyme is either free or bound in an enzyme-substrate complex.

Scientists can also use other graph forms to analyze the same data. The Lineweaver-Burke plot, also called the double reciprocal plot, uses the reciprocal values from the Michaelis-Menten graph. On this plot, the y-intercept equals 1/Vmax and the x-intercept equals -1/KM. It is often used to estimate KM and Vmax and to visually distinguish competitive, non-competitive, and uncompetitive inhibitors.

Other rearrangements of the Michaelis-Menten equation include the Eadie-Hofstee plot and the Hanes-Woolf plot. These graphs are also used to determine kinetic parameters. Together, these methods help scientists compare reaction behavior and understand how enzymes respond to substrate concentration and inhibitors.

Graphing Enzyme Kinetics Data

the first law of thermodynamics

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the-equilibrium-binding-constant-and-binding-strength

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introduction to enzyme kinetics

Enzyme kinetics uses graphs to show how fast a biochemical reaction happens. Scientists measure the initial reaction rate, or velocity (Vo), at different substrate concentrations ([S]). They may also run trials with inhibitors or other molecules that change the reaction rate. The results are often plotted as Vo against [S]. For many single-substrate reactions, the data fits the Michaelis-Menten equation. This equation, named after Leonor Michaelis and Maud Menten, helps estimate the maximum...

turnover number and catalytic efficiency

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introduction-to-mechanisms-of-enzyme-catalysis

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atp energy storage and release

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key terms and concepts

Learn how enzyme kinetics data is graphed with Michaelis-Menten, Lineweaver-Burke, Eadie-Hofstee, and Hanes-Woolf plots to estimate Vmax and KM.

Graphing Enzyme Kinetics Data | JoVE K12

cell biology

JoVE Core Cell Biology illustrates complex cellular processes in easy-to-understand yet comprehensive animated video lessons. This collection focuses on the essential components and functions of cells, including organelles and membranes, cellular transport, and cell energetics. It is complemented by scientist-in-action videos that demonstrate the application of cell biology in real-world research experiments.

Virginia  Standards of Learning

HIgh School

BIO.2

BIO.2.c

Chemistry

CH.7

CH.7.f

Florida Department of Education

High School

Life Science

SC.912.L.18

SC.912.L.18.4

SC.912.L.18.11

Texas Essential Knowledge and Skills

BIO.11

BIO.11.B

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Nucleic Acid Structure

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ATP Energy Storage and Release

ATP and Macromolecule Synthesis

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LS.Bio.1.1

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Enzyme kinetics studies the rates of biochemical reactions. Scientists monitor the reaction rates for a particular enzymatic reaction at various substrate ...

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Ligand Binding and Linkage

Cooperative Allosteric Transitions

Ribozymes

Carry out investigations to illustrate how enzymes act as catalysts for biochemical reactions and how environmental factors affect enzyme activity.

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Eukaryotic Compartmentalization

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Prokaryotic Cells

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Cytoplasm

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The Nucleus

The nucleus is a membrane-bound organelle that acts as a control center in a eukaryotic cell. It contains chromosomal DNA, which controls gene expression ...

Endoplasmic Reticulum

Endoplasmic ReticulumThe endoplasmic reticulum (ER) is an extensive network of membranous sacs and tubules in eukaryotic cells, continuous with the outer ...

Ribosomes

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Lysosomes

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Peroxisomes

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LS.Bio.1.3

Analyze how the relationship between structure and function supports life processes within organisms.

Graphing Enzyme Kinetics Data

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