+
+Unsaturation also influences the ability of a lipid molecule to leave
+a membrane. If a molecule has an unsaturation level which is different
+from the surrounding membrane, it will be more likely to leave the
+membrane. The more different the unsaturation level is, the greater
+the propensity for the lipid molecule to leave. However, a vesicle
+with some unsaturation is more favorable for lipids with more
+unsaturation than the equivalent amount of less unsatuturation, so the
+difference in energy between unsaturation is not linear. Therefore, an
+equation with the shape
+$x^{\left|y^{-\left<un_\mathrm{ves}\right>}-y^{-un_\mathrm{monomer}}\right|}$
+where $\left<un_\mathrm{ves}\right>$ is the average unsaturation of
+the vesicle, and $un_\mathrm{monomer}$ is the average unsaturation. In
+this equation, as the average unsaturation of the vesicle is larger,
+
+\textcolor{red}{I don't like this equation; the explanation above
+ seems really contrived. Need to discuss.}
+