What is a Living Cell?

A living cell is a self-contained, self-assembling, self-adjusting, self-perpetuating istohermal system of molecules that extracts free energy and raw materials from its environment.

The cell carries out many consecutive reactions promoted by specific calatysts, called enzymes, which it produces itself.

The cell maintains itself in a dynamic steady state, far from equilibrium with its surroundings. There is great economy of parts and processes, achieved by regulation of the catalyctic activity of key enzymes.

Self replication through many generations is ensured by the self-repairing, linear information-coding system. Genetic information encoded as sequences of nucleotide subunits in DNA and RNA specifies the sequence of amino acids in each distinct protein, which ultimately determines the three dimensional structure and function of each protein.

Many weak (noncovalent) interactions, acting cooperatively, stabilize the three dimensional structures of biomolecules and supramolecular complexes.