Final answer:
Cholesterol within the plasma membrane manages the effects of temperature on membrane fluidity but is not necessarily present in higher amounts at higher temperatures. It acts as a buffer to maintain optimal fluidity across varying temperatures.
Step-by-step explanation:
In animal cells, cholesterol is a vital component of the plasma membrane that influences its fluidity. Cholesterol helps to manage the effects of temperature; at high temperatures, it functions to reduce membrane fluidity, hence maintaining the membrane's proper function. While cholesterol does perform this buffering action, it is not necessarily present in greater amounts at higher temperatures; its concentration in the plasma membrane is optimized to maintain the needed fluidity and rigidity balance across different temperatures.
At higher temperatures, membranes naturally become more fluid due to the increased movement of phospholipids. Cholesterol acts to stabilize this fluidity and prevent the membrane from becoming too permeable by filling in the gaps between phospholipids. Conversely, in cold environments, cholesterol helps to prevent the membrane from becoming too rigid. Cholesterol also aids in organizing clusters of transmembrane proteins into lipid rafts and contributes to the overall structural integrity of the membrane.