3.2 Environmental Impacts on Enzyme Function

Explain how changes to the structure of an enzyme may affect its function.

• Change to the molecular structure of a component in an enzymatic system may result in a change to its function or efficiency.
  • i. Denaturation of proteins, such as enzymes, oc curs when the protein structure is disrupted by a change in temperature, pH, or chemical environment, eliminating the ability to catalyze reactions.
  • ii. Environmental temperatures and pH outside the optimal range f or a given enzyme will cause changes to its structure (by disrupting the hydrogen bonds), altering the efficiency with which it catalyzes reactions.
• In some cases, enzyme denaturation is reversible, allowing the enzyme to regain activity.

Explain how the cellular environment affects enzyme activity.

• The relative concentrations of substrates and products determine how efficiently an enzymatic reaction proceeds.
• Higher environmental temperatures increase the average speed of movement of molecules in a solution, increasing the frequency of collisions between enzymes and substrates and therefore increasing the rate of reaction until the optimal temperature is achieved.
• Competitive inhibitor molecules can bind reversibly to the active site of the enzyme. Noncompetitive inhibitors can bind to allosteric sites, changing the activity of the enzyme.