A mixture of lipids is applied to a silica gel column and the column is washed with increasingly polar solvents. The mixture consists of phosphatidylserine, phosphatidylethanolamine, phosphatidylcholine, cholesteryl palmitate (a steryl ester), sphingomyelin, palmitate, n-tetradecanol, triacylglycerol, and cholesterol. In what order will the lipids elute from the column from the first to elute from the column to the last

Explanation:

Silica gel is polar, therefore the non-polar (hydrophobic) lipids will elute first whereas the polar (hydrophilic) lipids will elute later. In the given lipid sample the order from non-polar to polar is:

triacylglycerol, cholesterol, sphingomyelin, phosphatidylserine.

Hence the order of elution from the first to the last will also be the same. i.e,triacylglycerol( elutes1st), cholesterol, sphingomylein, phosphatidylserine (elutes last).

the positions which points up in upward carbon and down in downward carbon are axial

and vice versa holds true for equatorial positions

so the correct answer with labelled diagram will be