Why are psychrophilies membranes contain polyunsaturated fatty acids while thermophiles membranes contain highly saturated fatty acids?

Answer 1

saturated fats are solid at a higher temperature. Think of bacon fat vs. olive oil: the bacon fat is solid at RT while the olive oil is liquid at RT.

Answer 2

Hello Carlton,

I think you ask an excellent question. Psychrophiles inhabit environments that are permanently cold, thus their cell membranes possess a high level of polyunsaturated fatty acids that will remain more fluid in cold temperatures. Thermophiles (or extremeophiles), however, inhabit hot environments, thus their cell membranes possess high levels of saturated fatty acids that have higher melting points than saturated fatty acids. Compare, for example, the melting points of vegetable oils (unsaturated fatty acids) vs. animal fats (saturated fatty acids).

Hope this helps.

All the best,

Randall