Question

Which of the following processes will most likely occur when you transfer a bacterial culture from 37 degree C to 10 degree C?

the bacteria will start synthesizing cholesterol

the bacteria will remove cholesterol from their membranes

the bacteria will reduce the number of unsaturated bonds in the fatty acid tails of their phospholipids

the bacteria will increase the synthesis of phospholipids with very long fatty acid tails and insert these into their membranes

the bacteria will increase the synthesis of phospholipids with unsaturated fatty acid tails and insert these into their membranes

Answer 1

Answer : The correct option is E (the bacteria will increase the synthesis of phospholipids with unsaturated fatty acid tails and insert these into their membranes)

Explanation : Saturated fatty acids pack well into a paracrstalline form but the kinks in the unsaturated fatty acids inteferes with this packing hinders the formation of paracrystalline state. Higher the proportion of saturated fatty acids the higher is the transistion temperature of the membrane. For example, Psychrophiles contain a high content of unsaturated fatty acids which help to maintain as semisolid state of the membrane at low temperatrure (membranes composed of predominantly saturated fatty acids would become waxy and nonfunctional at low temperatures).