Fort Rucker. Fort Rucker is a U.S. Army post located mostly in Dale County, Alabama, United States. It was named for a Civil War officer, Confederate General Edmund Rucker.
The reason that the cell membrane is considered to be 'semi-permeable' is because there are certain materials that can pass through the cell membrane (e.g. hydrocarbons and oxygen cross through the cell membrane as they can be dissolved into the lipid layer-other examples include small polar molecules.he basic structure of the cell membrane consists of layers. The cell membrane is a phospholid bi-layer. It is made up of proteins and lipids (also known as the phospholipid).
All cells are surrounded by a plasma membrane. The membrane is composed of a phospholipid bilayer arranged back-to-back. The membrane is also covered in places with cholesterol molecules and proteins. The plasma membrane is selectively permeable and regulates which molecules are allowed to enter and exit the cell.ll cells are surrounded by a plasma membrane. The membrane is composed of a phospholipid bilayer arranged back-to-back. The membrane is also covered in places with cholesterol molecules and proteins. The plasma membrane is selectively permeable and regulates which molecules are allowed to enter and exit the cell.