The energy transformations during chemical and biological processes, established that the sum total of all these forms of energy is constant: energy, like matter, neither created nor destroyed. It also found that energy and matter are mutually convertible. This principle states that energy is neither created nor destroyed but only transformed from one form to another. In these transformations the total energy remains constant (Landau, 1999).
The law of conservation of energy states that:
There cannot be anything capable of generating energy.
There cannot be anything able to get rid of energy.