ABSTRACT
A key development in the consolidation of the cell theory of disease was the construction of the prototype electron microscope by Ruska in Germany in 1933. The cell membrane is not merely a membranous bag housing the cytoplasm and nucleus, but serves as a semipermeable membrane capable of maintaining large chemical gradients between the intracellular and extracellular compartments. Mitochondria generate the energy requirements of the cell. They are the seat of aerobic respiration, in which cytochrome oxidase catalyses the four-electron reduction of O2 to H2 0, a process leading to the generation of high-energy adenosine triphosphate. Cell injury is classified as being either reversible or irreversible. There is no morphologically defined point that marks the passage of injury from reversible to irreversible. The term necrosis describes the morphological changes that follow the death of cells contained within a living organism.
