Membrane Structure and Function

The cell and, in the case of eukaryotic cells, its internal components are surrounded by one or more membranes. Because of membranes the environment inside a cell or in different parts of a cell can be different from the external environment or other areas of the cell. Membranes help maintain this difference and perform a variety of related function. To perform their functions, membranes contain specific proteins and lipid components. Membranes are essential for the integrity and function of the cell.

Membranes:

• protect the cell
• regulate passage of materials in and out of cell or among areas within the cell
• allow cells to receive or transmit signals through receptors that only allow select chemicals to bind to them
• allow cell recognition
• provide sites that anchor internal filaments or to external components. This allows the cell to maintain its shape and perhaps move.
• help compartmentalize internal components
• provide sites to which enzymes can bind and catalyze reactions.

Practice identifying components of cell membrane

Practice identifying components of cell membrane

Practice identifying membrane protein diversity

Functions of plasma membrane proteins