Energy is defined as the ability to what

Energy is the ability to do work.

Some types of energy are potential energy, kinetic energy, nuclear energy, thermal energy, and there are many more.

What's common in all of those energies I have listed above is that energy no matter what kind you mention all have the ability to do work but some do it in different ways.

an active site is a region that is present on an enzyme where the reactants or the substrate molecules we can say bind and experience a chemical reaction. the substrate is basically a reactant whose concentration is changing and that is converting into a product after binding at the active site of an enzyme

the median of the data is 4.5.