Let's see how enzymes affect rate of reaction and help in industrial manufacturing in A-Level Chemistry!
Enzymes are usually present only in small amounts. Enzyme-catalysed reactions have different rate equations at high and at low substrate concentrations.
Low Substrate Concentration
At low concentrations of substrate, the rate equation is
Rate = k [E][S]
There are plenty of active sites for the substrate to bind to –so doubling the substrate concentration doubles the rate of reaction.
The rate of reaction depends on how frequently enzymes encounter substrates.The reaction is first order with respect to the substrate.
High Substrate Concentration
At high concentrations of substrate, the rate equation is
Rate = k [E]
This is because all the active sites on the enzyme molecules have become saturated. The reaction becomes zero order with respect to the substrate.
Enzymes in industry
Enzymes are used increasingly as catalysts in industry because:
They are specific -
they can select a particular substrate from a feedstock containing a mixture of reactants
They work effectively in low temperatures -
this helps reduce the energy costs
They work well in aqeuous environments -
Reduce the need of organic solvents which can be flammable and damaging to the environment.
Convert reactant to product in a one-step reaction -
increase the percentage atom economy
Drafted by Eunice (Chemistry)
References:
https://www.cs.mcgill.ca/~rwest/wikispeedia/wpcd/wp/e/Enzyme_kinetics.htm
https://www.pathwayz.org/Tree/Plain/ENZYMES+%26+SUBSTRATE+CONCENTRATION
https://www.researchgate.net/figure/Examples-of-application-of-enzymes-in-industry-agriculture-and-the-environment_fig1_268063448