Question

Bacteria that live in extreme temperatures (either very hot or very cold) have substantially different fatty acids in their phospholipids.

1. How would these fatty acids differ between bacteria living in hot and cold extremes? Why?
2. What other molecules might differ in the membranes of bacteria living at these extreme temperatures. Why?

Answer 1

Those bacteria which live in extreme cold condition, need to protect cell from freezing so they have unsaturated fatty acyl chain which has kinks due to double bonds, so can't pack tightly and prevent membranes from freezing. Also their chain length of fatty acyl is small as small chain have less surface for wander vaal interaction.

Those bacteria which live in extreme hot condition, need to protect their membrane from melting or breakage, so they have saturated fatty acyl chain in their membrane which can pack tightly due to absence of double bond. Also their chain length is larger as larger chain have more surface for wander Waal interaction.

These bacteria have enzyme which are stable at very low temperature ( zero degree Celsius) in cold area living and those bacteria which live in hot area, their enzyme are stable at that high temperature.