Question

The efficiency of enzymes is affected by the temperature and pH change, why?

• A. The energy of activation will be raised or lowered
• B. The three-dimensional protein structure of enzymes is altered
• C. The changes affect substrate surfaces and make them unrecognizable
• D. All enzymes work best at normal body temperature and a neutral pH
• E. Cofactors are not available under abnormal conditions

Answer 1

The correct option is B The three-dimensional protein structure of enzymes is altered

The enzymes show the best activity at optimum temperature and pH. When there is a change in the temperature, the structure of the enzyme is changed. The tertiary structure of the enzyme is responsible for the enzymatic activity. Any change in the temperature or pH will result in the breaking of the peptides or disulphide bonds. This will disturb the tertiary structure of the enzyme. At the lower temperature, the enzymes get deactivated while, at a higher temperature, it gets denatured. The optimum pH for an enzyme varies with the location.

Thus, the correct answer is option B.