Which of the Following Factors Would Tend to Increase Membrane

Question

Which of the following factors would tend to increase membrane fluidity?
A) a greater proportion of unsaturated phospholipids
B) a greater proportion of saturated phospholipids
C) a lower temperature
D) a relatively high protein content in the membrane
E) a greater proportion of relatively large glycolipids compared with lipids having smaller molecular masses

Accepted Answer

Unsaturated fatty acid tails in phospholipids have kinks in the carbon chain that prevent tight packing of the tails, increasing the space between the molecules and therefore increasing fluidity.

Answer: C
 Lower temperatures tend to slow down molecular motion, making the membrane less fluid.

Answer: E
 Glycolipids tend to have larger molecular masses compared to other lipids, and a greater proportion of these larger molecules in the membrane would increase the space between the molecules and therefore increase fluidity.