What Can Be Found in the Cell Membrane? Another type of lipid in the cell membrane is cholesterol, which helps the membrane maintain its structure - it prevents the phospholipids from moving too far apart or too close together, keeping it flexible without letting too many substances permeate through. extracelluiar space transmembrane protein (or integral protein) glycoprotein phospholipid gycolipid cartbohydrate cholesterol Embedded in the phospholipid bilayer are proteins that aid in movement and cell recognition. Proteins called integral proteins go all the way through the bilayer. An example of an integral protein is a transport protein. While smaller molecules can easily pass through the phospholipid bilayer, larger molecules like glucose utilize these transport proteins to help move across cell membranes without the use of energy. Peripheral proteins, on the other hand, are found oniy on one side of the membrane. cytoskaleton cytopiaam Lipids and proteins may also have chains of carbohydrates attached to them on the extracellular (out) side of the cell. These carbohydrate chains help cells recognize and signal one another. If a carbohydrate chain is attached to a lipid, it is called a glycolipid. If a carbohydrate chain is attached to a protein, it is called a glycoprotein. It is important to note that these components in the cell membrane are not "stuck" in place, but are able to move around in the phospholipid bilayer. The cell membrane is constantly vibrating, creating small openings within the structure. Therefore, the phospholipids can allow water and other smaller molecules to pass through into or out of the cell, without the use of energy. 7. What is the function of cholesterol in the membrane? 8. Describe the difference between integral proteins and peripheral proteins. 9. What is the function of a transport protein? 10. What is the function of the carbohydrate chains? 11. What is the prefix added in front of -lipid or -protein if a carbohydrate chain is attached?