Why does an enzyme not work as well if its active site is changed?

Enzymes are generally very carefully formed in order to catalyze a specific reaction for a specific molecule. The active site is folded in such as way to just allow the desired substrate to fit into it (like a puzzle piece), so changing the site will make it more difficult for this binding to occur. If the binding is more difficult the reaction will be inhibited, hence the enzyme won't work as well(if at all).

Mitochondria is the cell organelle that produced the energy that is needed in the body system in form of atp, that is why it is called the power house of the cell. energy is needed by the living organisms to carry out the activities which sustain life.  if the mitochondria is destroyed atp will not be produced. if the mitochondria is destroyed, energy production will stop and the affected living organism will not have the energy to carry out the necessary life processes; this will lead to the death of the organism.