Question

Name and explain the manner in which at least three factors can influence the speed of an enzymatic reaction. How do cells regulate the activity of enzymes?

Answer 1

The three factors which influence the speed of an enzymatic reaction are-

1. pH- Enzymes are affected by a change in pH. If the pH is lower or higher than the optimal pH then the enzyme activity decreases. Most of the enzymes work at neutral pH. The optimal value will vary from one enzyme to the other.
   
2. Temperature- The rate of a reaction in enzyme activity increases as the temperature is raised. Reactions occur faster at warmer temperatures because of the rate of collision increases. If the temperature is too high then the enzyme may fail to function.
   
3. Enzyme concentration- Adding an enzyme molecule will speed up the reaction until a saturation point is reached. As the concentration of enzyme is increased the velocity of reaction also increases.
   

The cells use specific molecules to regulate enzymes in order to promote or inhibit certain chemical reactions. Molecules that bind to sites of an enzyme other than the active sites can regulate the enzyme.