This post comes to us from "Biochem write up"
The aim of this practical is to carry out TLC in which the substances we wish to separate are absorbed onto the thin layer. Lipids are determined by isolation and the ability to purify the substance. Due to the way the substances interact with the matrix in different ways we are able to seperate them. Substances which interact strongly with the matrix but not with the solvent will move very slowly and those soluble in the solvent will dissolve easily and be carried along the solvent.
Egg yolk contains trioleine, cholesterol palmitate and phosphatidylethonolamine, The most polar of the three elements is the second element. It hardly moves up the TLC because of the presence of several polar groups; phosphate groups, amine groups and several oxygens , and cholesterol palmitate being the most non polar.