The upper limit of cell size is probably set by the rate of diffusion of solute molecules in aqueous systems. - Albert L. Lehninger

Organisms possess extraordinary attributes, properties that distinguish them from other collections of matter. What are these distinguishing features of living organisms?

The remarkable similarity of metabolic pathways and gene sequences across the phyla argues strongly that all modern organisms are derived from a common evolutionary progenitor by a series of small changes (mutations), each of which conferred a selective advantage to some organism in some ecological niche.

Virtually every chemical reaction in a cell occurs at a significant rate only because of the presence of enzymes.