TL - Enzymes Flashcards
What are enzymes?
Proteins which speed up a reaction by acting as biological catalysts
What are substrates?
The molecules that enzymes act on to speed up reactions
What is the active site?
The part of the enzyme that the substrate binds to to interact with the enzyme.
The active site is 3D and is part of the tertiary structure of the enzyme protein
Explain why enzymes have high specificity
They only work with specific substrates (usually only 1) because for the enzyme to work, the substrate has to fit into the active site. If the substrate’s shape doesn’t match the active site’s shape, then the reaction won’t be catalysed (called the lock and key model)
Define the optimum temperature for an enzyme and explain why it exists
At optimum temperature, the reaction rate is at a maximum (the enzyme works best at this temperature)
At low temperatures, the reaction is slow because the reactant molecules has low kinetic energy
At higher temperatures the reaction rate drops dramatically because the enzyme becomes denatured due to the change in tertiary structure of the active site
Define the optimum pH for an enzyme and explain why it exists
At optimum pH, the reaction rate is at a maximum (the enzyme works best at this pH)
At too low or too high pH, the rate of reaction decreases because the enzyme becomes denatured due to the change in tertiary structure of the active site
Define inhibitors and explain how they work
Inhibitors slow down a rate of reaction
1) Inhibitors are molecules with similar shape to the substrate
2) They compete with the substrate to bond to the active site, but no reaction follows. Instead they block the active site, so no substrate can fit in it
3) How much inhibition happens depends on the relative concentrations of inhibitor and substrate, as well as how strongly the inhibitor bonds to the active site
What part of the enzyme specifically binds to the substrate and what bonds are formed
Hydrogen bonds and van der Waals forces form between the substrate and the R groups of the enzyme’s amino acids
Describe what enzymes are used for in industry
Enzymes are widely used to:
1) Make commercial reactions proceed quickly at relatively low temperatures
2) Increase the yield of reactions and make them more selective
Explain how enzymes can reduce the environmental impact of industrial reactions
1) If the reaction is carried out at a lower temperature, less fuel is burned and less pollution is created
2) Higher yields can often mean less unreacted waste chemicals - again reducing pollution
3) Enzymes can also prevent side-reactions from occurring, reducing unwanted and potentially harmful by-products
