The Km (Michaelis constant) is a measure of how strongly an enzyme binds to its substrate.
In simple terms:
- It tells us the substrate concentration at which the enzyme works at half of its maximum speed.
Meaning of Km:
- A low Km means the enzyme binds the substrate tightly — it needs only a small amount of substrate to work efficiently.
- A high Km means the enzyme binds the substrate weakly — it needs more substrate to reach the same speed.
Importance of Km:
- It shows how efficiently an enzyme works with its substrate.
- It helps compare different enzymes or the same enzyme acting on different substrates.
- It gives insight into how enzyme activity might change in different conditions (like pH or temperature).
- It is used in enzyme kinetics to understand and control reaction rates in biological and industrial systems.
In short:
Km tells how easily an enzyme can bind its substrate —
- Low Km → strong binding, high efficiency
- High Km → weak binding, low efficiency