Question

Why do living things use enzymes instead of heat as a source of activation energy?

Answer 1

Its B ,  add sufficient heat would kill the living thing.

Answer 2

Answer:

The correct answer should be B: Adding sufficient heat would harm or kill a living thing.

Enzymes are the bio-catalysts which are used to increases the rate of biochemical reactions taking place in our body.

They increase the rate of a reaction by decreasing the activation energy. They do so by forming enzyme-substrate complex.

Our body does not use heat as a source of activation energy because:

1. The system has to give larger amount of heat as compared to uncatalyzed reaction. It increases the energy utilization of the body.
2. As the reactions are taking place in-vivo, the heat may harm or kill the living cells.
3. It also may alter the structure of biomolecules such as DNA, RNA, proteins, and even substrate itself.
4. In addition, heat is not specific as an enzyme is. It may alter more than one reaction at a time.
5. Enzymes are not consumed in the reaction and hence they can be used again and again but heat has to be supplied every time a reaction takes place.