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.
Tax wedge. The tax wedge is the deviation from equilibrium price/quantity as a result of a taxation, which results in consumers paying more, and suppliers receiving less. Following from the Law of Supply and Demand, as the price to consumers increases, and the price from suppliers decreases, the quantity that each wishes to trade will decrease.