The flexibility and fluidity of membranes that contain a large amount of unsaturated fatty acid acyl chains are due to

The correct answer would be - double bonds present in unsaturated fatty acid fatty acyl that put kinks in it.

Explanation:

The flexibility and fluidity of membranes depend on the three major facts that are saturated - unsaturated fatty acid acyl chain, how much cholesterols in them, and the ratio of various types of groups.

If unsaturated fatty acid cyl chains are compressed in the membrane the kinks (loosely packed) in their form. The bond in the compressed unsaturated fatty acid is double bond that puts kin in them push the very next phospholipid molecule away which leads to the flexibility and fluidity.

Thus, the correct answer is - double bonds present in unsaturated fatty acid acyl chain that put kinks in it.