AP BIOLOGY

Detailed explanation-1: -Cholesterol is also a key determinant of membrane fluidity: at high temperatures, cholesterol acts to stabilize the cell membrane and increase its melting point; while at low temperatures, it inserts into phospholipids and prevents them from interfering with each other to avoid aggregation [39].

Detailed explanation-2: -Cholesterol contains a tetracyclic ring structure and adopts a trans conformation, rendering the molecule a planar and rigid characteristics that increases membrane packing and contributes to the integrity and rigidity of cell membranes.

Detailed explanation-3: -Cholesterol molecules are positioned within the bilayer to link the fatty acid molecules and stabilize and strengthen the membrane.

Detailed explanation-4: -Cholesterol molecules are important for maintaining the consistency of the cell membrane. They strengthen the membrane by preventing some small molecules from crossing it. Cholesterol molecules also keep the phospholipid tails from coming into contact and solidifying.

Detailed explanation-5: -The function of cholesterol in the cell membrane is to stabilize the interactions between the phospholipids and prevent the membrane from getting too fluid or too flexible.