Question

The negative effect of excessive heat on enzyme function is that

• A. It alters the three-dimensional shape of the enzyme
• B. It alters the amino acid sequence of the enzyme
• C. It alters the composition of the active site of the enzyme
• D. It alters the shape of the substrate molecule
• E. It alters the chemical identity of the substrate

Answer 1

The correct option is A It alters the three-dimensional shape of the enzyme

On increasing the temperature, at first the rate of enzyme activity increases. This continues till about 37 degrees. Further increasing the temperature, the enzyme activity slows down and ultimately stops because at high temperatures, the enzyme gets denatured. Enzymes are proteins. At very high temperature, the bonds between amino acids gets broken.This leads to change in the shape of the enzyme.