Required practical 1 Flashcards
Describe the induced fit model of enzyme action:
The substrate enters the enzyme’s active site forming an enzyme-substrate complex. This then induces the enzyme active site to undergo a conformational change so it is completely complementary to the substrate. This puts pressure on the bonds in the substrate lowering the activation energy. The products are then removed and the enzyme active site returns to the original shape.
Why is the enzyme active shape specific?
The active site is specific and unique in shape due to the specific folded and bonding (ionic, hydrogen, and disulfide bridges) in the tertiary structure of the protein.
Name some factors that affect enzyme action:
pH, temperature, substrate and enzyme concentration, inhibitors
How does a competitive inhibitor affect enzyme action?
Competitive inhibitors have the same structure as the substrate and are also complementary to the enzyme slowing enzyme action. However, if you add enough substrate it will outcompete the competitive inhibitor and vice versa.
How does a non-competitive inhibitor affect enzyme action?
Non-competitive inhibitors bind to the allosteric site. This induces a change in the structure of the enzyme’s active site. Therefore the substrate is no longer complementary therefore slows enzyme action.
How does pH affect enzyme action?
Too high or too low a pH can denature an enzyme as it will interfere with the charges in the amino acids in the active site. This breaks the bond changing the active site. Therefore pHs away from the optimum slows enzyme action.
