Chemistry - Catalysts
The final factor affecting the rate of reaction is the presence (or not)
of a catalyst.
A catalyst increases the rate of a reaction without being used up. It does
this by providing a reaction pathway with a lower activation energy, which
increases the proportion of collisions with energy greater than the
activation energy. These aspects are emphasised again in the diagrams
Catalysts are not consumed during chemical reactions. They increase the
rate of a reaction but are recoverable and reusable at the end of the
Enzymes are probably the most efficient catalysts. Given that they are
responsible for controlling the thousands of reactions occurring in our
bodies, great efficiency is essential. Whereas inorganic catalysts can work
for a number of different reactions and over a range of temperatures,
enzymes are reaction-specific and cease to function effectively above 45C.
Previous | Next