H1 Biology and H2 Biology
What are the effects of substrate concentration on the rate of enzyme-catalysed reactions?
Notes from the video ‘H2 Biology Tuition | H1 Biology Tuition | Effect of Substrate Concentration on Rate of Enzyme-Catalysed Reaction’:
In this Biology tutorial, we would learn about the effects of substrate concentration on the rate of enzyme-catalysed enzymes.
Low Substrate Concentration
At low substrate concentrations, the active sites of enzymes are readily available to catalyze the reaction so the substrate concentration is limiting. An increase in the substrate concentration results in increase in the frequency of effective collisions between the enzyme and substrate and the rate of formation of enzyme-substrate complexes.
Increasing Substrate Concentration
As substrate concentration continue to increase, the rate of reaction increases at a decreasing rate as more active sites are occupied by substrates. Substrate concentration is no longer the only limiting factor.
High Substrate Concentration
Above a certain concentration, all available active sites are saturated, substrate concentration is no longer limiting. Instead, enzyme concentration becomes limiting, and further increases in substrate concentration will not increase the rate of reaction.