The cell membrane is the basic structural part of the cell that encapsulates its contents
and defines the intra- and extra- cellular space. It provides the integrity of the cell
structure, preventing contents of the cell from leaking out, it regulates the transport
of molecules across the cell (ions, nutrients etc.) and maintains the cell potential. Furthermore,
the cell membrane serves as a protective barrier, which prevents transport
of undesired molecules and pathogens into the cell. Molecular recognition mechanisms
at the membrane surface, which allow the cell to detect a pathogen, also play an
important role in cell signalling, and other forms of cell-cell interactions.
The most accepted representation of biological membranes, which was introduced by
Singer and Nicolson in 1972, is the fluid mosaic model (Figure 1.1) [1]. In this description,
a membrane is composed mainly of lipids and proteins that form a thin (from
6 nm to 10 nm width) bilayer film with membrane proteins either embedded in this
structure or located at the surface of the membrane. Cell membranes consisting of
several layers of this type are also possible. Other components of the cell membrane
may include cholesterol, sugars and other organic species. The membrane structure is
highly flexible and allows the lateral diffusion of both proteins and lipids
The cell membrane is the basic structural part of the cell that encapsulates its contentsand defines the intra- and extra- cellular space. It provides the integrity of the cellstructure, preventing contents of the cell from leaking out, it regulates the transportof molecules across the cell (ions, nutrients etc.) and maintains the cell potential. Furthermore,the cell membrane serves as a protective barrier, which prevents transportof undesired molecules and pathogens into the cell. Molecular recognition mechanismsat the membrane surface, which allow the cell to detect a pathogen, also play animportant role in cell signalling, and other forms of cell-cell interactions.The most accepted representation of biological membranes, which was introduced bySinger and Nicolson in 1972, is the fluid mosaic model (Figure 1.1) [1]. In this description,a membrane is composed mainly of lipids and proteins that form a thin (from6 nm to 10 nm width) bilayer film with membrane proteins either embedded in thisstructure or located at the surface of the membrane. Cell membranes consisting ofseveral layers of this type are also possible. Other components of the cell membranemay include cholesterol, sugars and other organic species. The membrane structure ishighly flexible and allows the lateral diffusion of both proteins and lipids
การแปล กรุณารอสักครู่..
