Question

Why is it important to life that interactions be weak, noncovalent interactions?

Answer 1

In this case, remember that non-covalent interactions does not requires a sharing of electrons, making this type of interaction a weak interaction. In the opposite case, the covalent bonds are based in the electron sharing between two or more atoms.

It is important that a big part of interactions in living beings were non covalent since it does not represent a permanent change regarding the structure of molecules. For example, the interaction between an enzyme and its substrate is mediated by a non covalent bond which is a weak bond that will serve to catalyze the reaction. Once the enzyme accomplish its task, it will separate from the substrate and other substrate will bind to the same active site of the enzyme. Without a non covalent interaction, the substrate would be permanently attached to the enzyme and catalytic reactions would not exist.

Remember that within a cell, there are different reactions occurring constantly and they depends on non covalent interaction.