Please enable JavaScript.
Coggle requires JavaScript to display documents.
Enzymes (Enzyme and Active Site (enzyme (globular protein acting as…
Enzymes
Enzyme and Active Site
-
active site
region on the surface of an enzyme to which substrates bind and which catalyses the reaction involving the substrate
-
-
Collision
-
catalysis only occurs if the substrate is in a liquid, as this leads to the random movement of molecules, hence increasing chances of collision.
when the substrate binds to the active site, the energy to convert substrate into product is reduced (lower activation energy).
Affecting Activity
temperature
In liquids, particles are in continuous random motion. When heated, kinetic energy is added to them, making them move around faster. Chances of collisions increases and therefore so does enzyme activity.
Enzymes do, however, have an optimum temperature. When heated, bonds vibrate. The stronger the vibrations the more chances of the bonds breaking. This leads to denaturation.
pH
most enzymes have an optimum pH, that is, the pH at which they are most efficient. As the pH diverges from the optimum, the enzyme's activity decreases. Excessive deviation from the optimum pH causes the enzyme to change shape up to the point where it denatures.
substrate concentration
as the substrate concentration increases, so do chances of collision. This increases the enzyme's activity. However, once all active sites are taken up, further substrate concentration increase will no longer affect the enzyme's activity.
Denaturation
enzymes can be denatured, that is, the active site is altered
can be irreversibly altered at certain conditions (high temperature, change of pH)
denaturation often causes enzymes to become insoluble, forming a precipitate
Enzyme Activity
-
three different stages
- substrate binds to the active site of the enzyme.
- substrate changes into chemical substances consisting in the product of the reaction.
- the product separates from the active site, which is left empty for other reactions to occur.