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.
Volume [edit]. For a rectangle based wedge, the volume is. where the base rectangle is a by b, c is the apex edge length parallel to a, and h the height from the base rectangle to the apex edge. wedge is a subclass of the prismatoids with the base and opposite ridge in two parallel planes. A wedge can also be classified as a digonal cupola. Comparisons: 1  A wedge is a parallelepiped where a face has collapsed into a line.