Becker's World of the Cell 9th Edition by Lewis Kleinsmith, Jeff Hardin, Gregory Paul Bertoni

Exercise 8

Membrane Fluidity and Temperature. The effects of temperature and lipid composition on membrane fluidity are often studied by using artificial membranes containing only one or a few kinds of lipids and no proteins. Assume that you and your lab partner have made the following artificial membranes:
Membrane 1: Made entirely from phosphatidylcholine with saturated 16-carbon fatty acids.
Membrane 2: Same as membrane 1, except that each of the 16-carbon fatty acids has a single cis double bond.
Membrane 3: Same as membrane 1, except that each of the saturated fatty acids has only 14 carbon atoms.
After determining the transition temperatures of samples representing each of the membranes, you discover that your lab partner failed to record which membranes the samples correspond to. The three values you determined are -36°C,
23°C, and 41°C. Assign each of these transition temperatures to the correct artificial membrane, and explain your reasoning.