Question

How would an organism maintain membrane fluidity in an environment where temperatures fluctuated from very high to very low?

a) Increase cholesterol content
b) Decrease phospholipid content
c) Increase saturated fatty acids
d) Decrease unsaturated fatty acids

Answer 1

An organism can adjust its membrane fluidity in fluctuating temperatures by altering the unsaturated and saturated fatty acid content, as well as the cholesterol content, of the membrane lipids.

Step-by-step explanation:

To maintain membrane fluidity in an environment with fluctuating temperatures, an organism would adapt by changing the composition of its cellular membranes. At lower temperatures, it's beneficial to increase the content of unsaturated fatty acids, which contain kinks due to the presence of C=C double bonds that prevent the fatty acid tails from packing closely together, thus maintaining fluidity and preventing the membrane from solidifying. In contrast, at higher temperatures, an organism might increase the saturated fatty acid content or cholesterol content to stabilize the membrane and prevent it from becoming too fluid. Cholesterol acts as a buffer, enhancing fluidity at lower temperatures and preventing excess fluidity at higher temperatures.