The ability of Prokaryotic microorganisms to move compounds into the cell, and to remove waste products of metabolism out of the cell, is crucial for the survival of the cell. Some of these functions are achieved by the presence of water-filled...

The membranes of bacteria function to give the bacterium its shape, allow the passage of molecules from the outside in and from the inside out, and to prevent the internal contents from leaking out. Gram-negative bacteria have two membranes that make...

Cell membranes or plasma membranes surround cells, separating the cytoplasm and organelles on the inside from the extracellular fluid on the outside. Several cell organelles (mitochondria, endoplasmic reticulum, and Golgi bodies) are also bounded by...

Surrounding each cell within the nervous system is a highly complex lipid bilayer called a membrane formed by microscopic phospholipid molecules. Phospholipids have a round, negatively charged "head" consisting of phosphate, choline, and glycerol; and...

The plasma membrane is a very thin, continuous sheet of phospholipids and proteins that surrounds all living cells and separates them from their external environment. This membranous barrier maintains conditions within the cell and creates an internal...

The cell membrane (also called the plasma membrane, plasmalemma or "phospholipid bilayer") is a semipermeable lipid bilayer found in all cells.[1] It contains a wide variety of biological molecules, primarily proteins and lipids, which are involved in a...