Question

A high fever is dangerous to the human body because it
A) Denatures enzymes
B) Inactivates enzymes
C) Coagulates enzymes
D) Boils fluids inside the body

Answer 1

Enzymes (except RNA enzymes) are proteinaceous. Enzymes exist in crystal form. They are substrate and reaction specific and thereby work at a particular temperature and pH.

Complete answer: Enzymes are proteinaceous (except RNA enzymes) and have a tertiary structure. They have high molecular weight so they exist in crystal or colloidal form. Enzymes do not initiate a chemical reaction. They have low activation energy and they remain unchanged at the end of the reaction. Enzymes are substrate and reaction specific and work at a particular pH and temperature.
Enzymes work at an optimum temperature of 25-40 degrees Celsius. At low temperature, enzymes get inactivated and at high temperature, they get denatured (peptide bonds get denatured).
The rate of reaction doubles with every increase in 10 degree Celsius (temperature coefficient).
There are some enzymes that are temperature resistant. For example- enzymes of microorganisms living in hot springs up to 40-45 degrees Celsius and then start decreasing because of the molecular configuration of enzymes changes due to the breaking of electrostatic forces and bonds between molecules.
So, the answer is option A. denatures enzymes.

Note: Food can be preserved for long either at low temperature or by heating it regularly, as their enzymes get inactivated or denatured respectively. So, cold-blooded organisms undergo aestivation and hibernation due to the slowing down of their enzyme activity.
All enzymes work at a specific pH. Example- pepsin at 2, trypsin at 8.8, amylase at 6.7, etc. This sensitivity of the enzyme is based on the number of R groups necessary for its activity and the charge they carry.
With the increase in substrate concentration, the rate of reaction increases to some extent and then starts decreasing as no active site of an enzyme is left free to bind substrate molecules.