Prokaryotes 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.
3. countable noun. A wedge is an object with one pointed edge and one thick edge, which you put under a door to keep it firmly in position. 4. countable noun. A wedge is a piece of metal with a pointed edge which is used for splitting a material such as stone or wood, by being hammered into a crack in the material.
quadrant (Noun) One of the four sections made by dividing an area with two perpendicular lines. quadrant (Noun) The four regions of the Cartesian plane bounded by the x-axis and y-axis. quadrant (Noun) One fourth of a circle or disc; a sector with an angle of 90. quadrant (Noun) A measuring device with a graduated arc of 90 used in locating an altitude.