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Lipid Bilayer, Steroid, Fatty Acid Problems

Which fatty acid -palmitic, stearic, palmitoleic, or arachidonic, would have lowest m.p. and explain why.

Which would be chiral? A)glyceryl tripalmitate,B) glyceryl 1-stearate, 2,3 dipalmitate,C) glyceryl 2-stearate, 1,3-dipalmitate. Explain why.

A lipid is isolated and treated with boiling aqueous NaOH. The products obtained are sphingosine, sodium stearate,glucose,galactose and mannose. To which class would this lipid belong? Explain.

What is the major driving force in the formation of lipid bilayers?

Which amino acid, Lys or Val, would be more likely to be found in the transmembrane section of an integral membrane protein. Explain.

A certain membrane protein has palmitic acid covalently bonded to its N-terminal amino acid. The protein consists primarily of charged amino acids, particularly Lys and Arg. Do you think this would be a periperal or integral membrane protein? Why? What is the probable function of the palmitic acid?

Explain the orientation of polar and nonpolar amino acid side chains in the transmembrane sections of channel proteins (either alpha helix or beta sheet) and how this contributes to the function of these proteins?

How many chiral carbons does cholesterol have? Draw the structure and show them.

Why do phospholipids form bilayers rather than micelles?

Is prostaglandin synthase a peripheral or integral membrane protein?

Explain how the substrate of prostaglandin synthase, arachidonic acid, reaches the active site without passing thru an aqueous environment.

Explain why an unsaturated fatty acid will have a lower m.p. than a saturated fatty acid containing the same number of carbons.

The steroid hormone which is closest in chemical structure to cholesterol is?

A female lacks the enzyme which removes the methyl group from the 10 position of the steroid ring on testosterone. Discuss the possible physiological implications of this mutation.

Solution Summary

Questions about fatty acids, membrane proteins, steroids, lipid bilayers, prostaglandin synthase and arachidonic acid are answered in full detail with sources.