ABSTRACT
The cell is the canonical structural and functional unit of all
living organisms. Microbes exist as individual or clustered,
independent cells. Every cell has a cytoplasmic membrane
defining its boundary, separating its interior and environ-
ment, and regulating material transfers between the two.
Membranes of many microorganisms are surrounded by
walls for strength and protection. Membrane and wall
correspond to walls of an industrial factory.
