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.
A pitching wedge is a wedge used to hit a shot with higher and shorter trajectory than a 9-iron and a lower and longer trajectory than a gap wedge.his is for a number of reasons: first, before the term wedge became common for high-loft short irons, the pitching wedge was actually numbered as the 10-iron of a matched set, and to this day it follows the normal loft progression of the numbered irons.