Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
A schematic illustrating the complexity of natural cell membranes. The base structure of these barriers is a double layer of phospholipids. Transport proteins, sterols and other biomolecules are present in different parts of the membrane depending on the cell’s role and life cycle stage.
