Which of the following is a key component of cell membranes?

Cholesterol is a key component of cell membranes because it contributes to membrane fluidity and stability. It is interspersed among the phospholipids in the bilayer, which allows cell membranes to maintain their integrity and flexibility under various temperature conditions. Cholesterol helps prevent the membranes from becoming too rigid in cold temperatures and too fluid in warm temperatures, thus playing a crucial role in maintaining homeostasis within the cell.

While carbohydrates do play a role in cell membranes, mainly as part of glycoproteins and glycolipids involved in cell recognition and signaling, they are not structural components of the membrane itself in the same way that cholesterol is. Nucleic acids, which include DNA and RNA, are primarily involved in genetic information storage and transfer, rather than being structural components of membranes. Glucose is an important energy source for cells but does not function as a component of the membrane structure. Therefore, cholesterol stands out as an essential component supporting the proper functioning of cell membranes.