Enzymes

Question 1

State the effect of temperature on enzymatic reaction

Answer 1

As temperature increases, the kinetic energy of the substrate and enzyme molecules increases, thereby increasing the frequency of effective collisions between substrates and enzyme active sites. This increases the rate of formation of the enzyme-substrate complex and increases the rate of reaction. Enzyme activity is highest at xxx and all enzyme active sites are occupied. However, beyond the optimum temperature, the rate of enzyme activity starts to decrease as high temperature breaks the bonds that keep the enzyme protein in its specific shape. The active site loses its original shape and is no longer complementary to the substrate. The enzyme is therefore denatured and loses its catalytic function.

Question 2

State the effect of pH on enzymatic activity

Answer 2

At the optimum pH, the enzyme functions the most efficiently and the rate of reaction is at its maximum. Enzyme maintains its specific 3D conformation and so the enzyme active site is complementary to the substrate. However, beyond or below the optimum pH, the changes in the pH alter the bonding patterns of the enzyme active sites, thereby altering the unique 3D conformation of the active site of the enzyme. Hence the substrate is no longer complementary to the active site, no enzyme-substrate complex can be formed, therefore no product is formed. The enzyme is denatured.