Substrate

Definition

A substrate is the specific reactant that an enzyme acts upon during a biochemical reaction. It binds to the enzyme's active site, facilitating a chemical transformation.

5 Must Know Facts For Your Next Test

1. Substrates bind to enzymes at the active site forming an enzyme-substrate complex.
2. The interaction between an enzyme and its substrate is highly specific, often described by the 'lock and key' or 'induced fit' models.
3. Substrates are transformed into products through enzymatic catalysis, which lowers the activation energy of the reaction.
4. Enzyme activity can be affected by substrate concentration, pH, and temperature.
5. Competitive inhibitors can block substrate binding by occupying the active site of the enzyme.

Review Questions

• What role does a substrate play in an enzymatic reaction?
• How does an increase in substrate concentration generally affect enzyme activity?
• Describe how competitive inhibition affects substrate binding to an enzyme.

Related terms

Enzyme:

A protein that catalyzes biochemical reactions by lowering activation energy.

Active Site:

The region on an enzyme where the substrate molecules bind and undergo a chemical reaction.

Product: The molecules that result from the enzymatic transformation of substrates.