Pathology of Cell Membranes

Abstract

The cell is something like a city. It is surrounded by a belt line the plasma membrane) with specific spots reserved for entering or exiting the city. The belt line is linked to the administrative center of the city, the nucleus, through a complex maze of roads and streets. The administrative center may itself be surrounded by a parkway (the nuclear membrane). Between the maze of streets and roads are power plants (mitochondria), warehouses (storage sites such as those for glycogen and lipids), factories where new products (e.g., lipoproteins) are manufactured, and sanitation stations (detoxifying mechanisms, etc.). In the city food must be brought in, garbage and sewage must be removed, fabricated products must be transported from one part of the city to another or even be exported. Breaking the barriers of communication results in traffic jams, smuggling, and all sorts of catastrophies. Interruption of internal communications, for example, by a strike of public transportation or sanitation personnel, makes life uncomfortable, if not unbearable for everyone. Likewise, the cell is surrounded by a plasma membrane and contains a complex intracellular network of membranes delineating areas with more or less defined functions: the cytocavitary network, which includes the endoplasmic reticulum, the membrane that surrounds the area of cytoplasmic autodigestion (lysosomes), membranes surrounding the mitochondria, and membranes that surround the peroxisomes.