The Michaelis-Menten constant (Km) is a crucial factor in enzyme kinetics, which describes the substrate’s affinity for an enzyme and influences its activity. It is independent of the concentration of the enzyme, as long as the measurements are done under proper conditions for Michaelis-Menten kinetic analysis. For practical purposes, Km is the concentration of substrate that permits the enzyme to achieve half Vmax. An enzyme with a high Km has a low affinity for the substrate, and will act at a more or less constant rate, regardless of variations in the substrate concentration.
In biochemistry, Km is the simplest case of enzyme kinetics, applied to enzyme-catalyzed reactions of one substrate and one product. However, it does not vary with the concentration of the enzyme if the proper experiment is conducted. Km is a function of the enzyme structure, specifically at the active site, and does not change with the concentration of the enzyme. For practical purposes, Km is the concentration of substrate which permits the enzyme to achieve half Vmax.
The value of Km is inversely related to the affinity of the enzyme for its substrate. High values of Km correspond to low enzyme affinity for the substrate. In summary, the Km value of an enzyme can change with the concentration of the substrate, but it is not related to Vmax or the enzyme’s affinity for the substrate.
| Article | Description | Site |
|---|---|---|
| Does Km (Michaelis constant) vary with enzyme … | The answer is in the negative. The rate of reaction, represented by the constant “k,” is independent of the concentration of the enzyme if the experiment is conducted correctly. | www.researchgate.net |
| Why doesn’t km vary with enzyme concentration? | The Km value is dependent upon the specific structure of the enzyme, particularly at the active site. This remains constant regardless of the concentration of the enzyme. | www.quora.com |
| why doesn’t Km change even when Vmax does? : r/Mcat | The Km of an enzyme is not subject to change regardless of the concentration of the enzyme itself, unless there is an increase in the number of substrates that can bind to the enzyme. | www.reddit.com |
📹 Why Km does not change with the enzyme concentration
Why Km does not change with the enzyme concentration.
📹 AS Biology – The Michaelis-Menten Constant (Km)
AS Biology – Enzymes topic. Description of how to use vmax to calculate Km (the substrate concentration at which 1/2 Vmax is …
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