Final answer:
The assertion that cholesterol decreases the mobility of phospholipids in the cell membrane is false. Cholesterol actually regulates membrane fluidity across varying temperatures and contributes to other important cellular functions, stabilizing the membrane structure in a balanced manner.
Step-by-step explanation:
The statement "Cholesterol helps to stabilize the cell membrane while decreasing the mobility of the phospholipids" is False. Cholesterol is indeed an integral component of animal cell membranes and performs the function of controlling the membrane's rigidity, but it does not simply decrease the mobility of the phospholipids; rather, it maintains a balance in the membrane's fluidity.
Cholesterol interspersed between phospholipids in the cell membrane acts as a buffer. It prevents lower temperatures from overly restricting fluidity and higher temperatures from increasing it too much. This means that cholesterol actually maintains appropriate membrane fluidity across a range of temperatures, ensuring the cell's functionality. Moreover, cholesterol is located within the phospholipid bilayer of the membrane and contributes to various cellular functions, including organizing lipid rafts which are specialized domains within the membrane.