Which of the following is not a general feature of the lipid bilayer in biological membranes? a. the higher the proportion of unsaturated fatty acid chains in a membrane's phosphoglycerides, the lower the transition temperature of the membrane. b. individual lipid molecules are free to diffuse laterally in one surface of the bilayer. c. the polar headgroups of phospholipids, glycolipids, and cholesterol face towards the interior of the bilayer. d. self-assembly of a lipid bilayer in an aqueous environment is favored entropically because the process results in large increase in the entropy of water molecules. e. the distribution of phosphoglycerides in the two leaflets of bilayer membranes is asymmetric.