Definition - What does Substrate mean?
A substrate is a molecule that an enzyme acts on in order to stimulate biochemical reactions within a living organism. A substrate undergoes changes during a reaction to form a product whereas the enzyme does not undergo any changes and retains its original form. The density of the substrate is indicative of the speed with which the reaction occurs. This process forms the basis of the detection method of some drug tests.
WorkplaceTesting explains Substrate
A substrate and a molecule are formed uniquely so that they fit in the same way that a key does to a lock. The substrate acts as the key and the enzyme acts as the lock. The substrate connects to the part of the enzyme called the active site to form an enzyme-substrate complex. When the correct substrate and enzyme combine, the reaction is initiated (catalyzed). However, the reaction will not take place if the incorrect combination of enzyme and substrate occurs. When the reaction is complete, the substrate transforms into a product and separates from the enzyme active site, leaving the enzyme to bind with other substrates.