Question

Membrane lipids in tissue samples obtained from different parts of the leg of a reindeer show different fatty acid compositions. Which of the following statements is/are true?

Multiple answers: You can select more than one option

A

Because reindeer spend much time walking through ice and snow the proportion of unsaturated fatty acyl chains should increase from the top of the leg (warm) to the hoof (cold) to insure fluidity at low temperature.

B

Unsaturated fatty acids closer to the hoof have a lower melting point due to the presence of double bonds.

C

The presence of double bonds prevent unsaturated fatty acids from packing together tightly.

D

The presence of saturated fatty acids help membranes to remain fluid at low temperature.

E

Saturated fatty acid content should be higher at the top of the leg (warm compared to the hoof) exhibiting a higher melting point due to the absence of double bonds.

Answer 1

Right Answers will be including - option A, option B, option C and optionE .

The only wrong one is option D here because saturated fatty acids have comparatively high melting temperature.

Explanation - membranes generally madeup of lipid bilayer and protein molecules ( fluid mosaic model of singer and nikelson ) and some sugar molecules can be there. The fact here is, fluidity of the membrane is very important to move protein and lipid molecules from one position to another where they are needed after synthesis. ( For various purposes ).
These lipids can be saturated with no double bonds and higher melting temperature and unsaturated with single and double bonds with lower melting temperature. The double bonds here make kinks that made it break at low temperatures.
Now, low melting point means at low temperature its flid and flexible. Same , high melting point means it is fluid at comparatively high temperature.

Here, rain deer hooves experience much more lower temperature than the upper leg does as it goes through the snow. So, more unsaturated fatty acids in the membrane of the hooves assure its fluidity.