Membrane Fluidity and Lipid Composition

In the study of cellular structures, phospholipids are key components of membranes, providing both structural integrity and functional versatility. Phospholipids are amphipathic molecules, consisting of a hydrophilic (water-attracting) phosphate group and two hydrophobic (water-repelling) fatty acid tails. This unique structure allows them to form bilayers in aqueous environments, presenting a critical barrier that separates the internal environment of the cell from the external environment.

Recent studies emphasize the importance of unsaturated fatty acids in membrane fluidity, which plays a vital role in various cellular processes, including membrane permeability and protein function. It has also been shown that the presence of cholesterol within these membranes influences their fluidity and stability, especially at varying temperatures.

Given this context, which of the following statements accurately describes a property of membranes influenced by their lipid composition?