Humber Admissions Practice Test

How does cholesterol contribute to cell membrane function?

1. By aiding in cell division

2. By providing strength and fluidity

3. By facilitating passive transport

4. By connecting to carbohydrate molecules

The correct answer is: By providing strength and fluidity

Cholesterol plays a crucial role in maintaining the integrity and functionality of cell membranes. It contributes to strength by stabilizing the membrane structure, thus preventing it from becoming too rigid or too fluid. This stabilization is essential, as it allows the membrane to maintain its shape and integrity under various physiological conditions. Additionally, cholesterol helps to maintain fluidity by preventing the fatty acid chains of phospholipids from packing too closely together. This balance of strength and fluidity is vital for various functions, such as allowing for the movement of proteins within the membrane and facilitating proper cell signaling. In contrast, options that mention aiding in cell division, facilitating passive transport, or connecting to carbohydrate molecules do not accurately represent the primary role of cholesterol in cell membranes. These processes are influenced by other cellular components and mechanisms rather than being directly affected by cholesterol itself. Thus, the correct understanding of cholesterol’s role in providing both strength and fluidity to the cell membrane enhances our comprehension of cellular structure and function.