Michaelis–Menten enzyme kinetics
A simple enzyme–substrate mechanism predicts saturating initial rates.
Key knowledge
For the simple mechanism E + S ⇌ ES → E + P, a quasi-steady-state approximation gives a saturating initial-rate relation. The Michaelis constant is the substrate concentration at half the model's maximum rate; it includes binding and turnover rate constants.
Values and equations
v₀ = Vmax [S] / (Km + [S])
- v₀
- initial product-formation rate mol L⁻¹ s⁻¹
- Vmax
- model maximum rate at the stated enzyme concentration mol L⁻¹ s⁻¹
- [S]
- free substrate concentration mol L⁻¹
- Km
- Michaelis constant for the stated mechanism and conditions mol L⁻¹
Conditions and scope
- Use initial-rate conditions, substrate in sufficient excess, negligible reverse product reaction and approximately steady ES after its short transient.
- Cooperativity, multiple substrates, inhibition or changing enzyme activity require other models. Km is not generally a pure binding dissociation constant.
Sources · 1
References
Sources retain their recorded scope. A source link alone does not establish verification of every statement.
Evidence and review
MIT's scoped derivation, equations I.5–I.6.
2026-10-10 · Checked assumptions and units.
Entry details
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- bio-enzyme-kinetics
- Revision
- university-reference.1
- Structured reference record
- University reference