Army medical examiners were suspicious about the close proximity of the three bullet holes in Pat Tillmanâs forehead and tried without success to get authorities to investigate whether the former NFL playerâs death amounted to a crime, according to documents obtained by The Associated Press.
Membrane. Definition. noun, plural: membranes. (1) (biology) A thin layer of tissue covering a surface or lining a cavity, space or organ. (2) (biology) A cell membrane. (3) (chemistry) A thin pliable sheet of material that is permeable to substances in solution.Supplement. A biological membrane functions by protecting the surface or bodily organ.1) (biology) A thin layer of tissue covering a surface or lining a cavity, space or organ. (2) (biology) A cell membrane. (3) (chemistry) A thin pliable sheet of material that is permeable to substances in solution. Supplement. A biological membrane functions by protecting the surface or bodily organ.
The lipid bilayer is a thin polar membrane made of two layers of lipid molecules.These membranes are flat sheets that form a continuous barrier around all cells.rokaryotes have only one lipid bilayer-the cell membrane (also known as the plasma membrane). Many prokaryotes also have a cell wall, but the cell wall is composed of proteins or long chain carbohydrates, not lipids.