Definition
First Law of Thermodynamics
The First Law of Thermodynamics is a version of the law of conservation of energy, adapted for thermodynamic systems. It states that energy can neither be created nor destroyed in an isolated system; it can only be transformed from one form to another.
Overview
In any process, the change in the internal energy of a system is equal to the heat added to the system minus the work done by the system. This principle ensures that the total amount of matter and energy remains constant regardless of whether time runs forward or in reverse.
Obs
For biological systems, the First Law implies that the energy used for growth, movement, and computation must be balanced by an intake of energy (metabolism) from the environment.