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.
Golf Wedges. Rather than lightly swinging a pitching wedge or over-swinging a sand wedge, the gap wedge covers the difference in degrees and distance between those two. Lofted between 50Â° and 54Â°, the gap wedge allows you to perform your normal swing when you're between 80 and 100 yards away from the pin.