Lipids are not soluble in water. Are lipids polar or nonpolar molecules?

Which of the following solvents might be used to dissolve an oil stain?

a. water

b. CCl₄

c. diethyl ether

d. benzene

e. NaCl solution

What are some functions of lipids in the body?

Describe some similarities and differences in the structures of a saturated fatty acid and an unsaturated fatty acid.

Stearic acid and linoleic acid each have 18 carbon atoms. Why does stearic acid melt at 69 °C but linoleic acid melts at –5 °C?

Draw the line-angle formula for each of the following fatty acids:

a. palmitic acid

For each of the following fatty acids, give the shorthand notation for the number of carbon atoms and double bonds, and classify as saturated, monounsaturated, or polyunsaturated:

a. lauric acid

For each of the following fatty acids, give the shorthand notation for the number of carbon atoms and double bonds, and classify as saturated, monounsaturated, or polyunsaturated:

a. linoleic acid

How does the structure of a fatty acid with a cis double bond differ from the structure of a fatty acid with a trans double bond?

How does the double bond influence the dispersion forces that can form between the hydrocarbon chains of fatty acids?

Compare the structures and functional groups of arachidonic acid and prostaglandin PGE₁.

What are some effects of prostaglandins in the body?

How does an anti-inflammatory drug reduce inflammation?

What is the difference in the location of the first double bond in an omega-3 and an omega-6 fatty acid (see Chemistry Link to Health “Omega-3 Fatty Acids in Fish Oils”)?

Draw the condensed structural formula for the ester in jojoba wax that is formed from arachidic acid, a 20-carbon saturated fatty acid, and 1-docosanol, CH₃–(CH₂)₂₁–OH.

Draw the condensed structural formula for a triacylglycerol that contains stearic acid and glycerol.

Draw the condensed structural formula for a mixed triacylglycerol that contains two palmitic acid molecules and one oleic acid molecule on the center carbon of glycerol.

Safflower oil is polyunsaturated, whereas olive oil is monounsaturated. Why would safflower oil have a lower melting point than olive oil?

How does the percentage of monounsaturated and polyunsaturated fatty acids in olive oil compare to that of canola oil?

Identify each of the following processes as hydrogenation, hydrolysis, or saponification and give the products:

a. the reaction of palm oil with KOH

Identify each of the following processes as hydrogenation, hydrolysis, or saponification and give the products:

b. the reaction of glyceryl trilinoleate from safflower oil with water and HCl

Identify each of the following processes as hydrogenation, hydrolysis, or saponification and give the products:

a. the reaction of corn oil and hydrogen (H₂) with a nickel catalyst

Identify each of the following processes as hydrogenation, hydrolysis, or saponification and give the products:

b. the reaction of glyceryl tristearate with water in the presence of lipase enzyme

Use condensed structural formulas to write the balanced chemical equation for the hydrogenation of glyceryl trilinolenate, a fat containing glycerol and three linolenic acid molecules.

Use line-angle formulas to write the balanced chemical equation for the acid hydrolysis of glyceryl trimyristate (trimyristin).

Use condensed structural formulas to write the balanced chemical equation for the NaOH saponification of glyceryl trimyristate (trimyristin).

Describe the similarities and differences between triacylglycerols and glycerophospholipids.

Draw the condensed structural formula for the cephalin that contains glycerol, two palmitic acids, phosphate, and ethanolamine (ionized).

Identify the following glycerophospholipid, which is found in the nerves and spinal cord in the body, as a lecithin or cephalin, and list its components: 

Identify the following features of this phospholipid, which is abundant in the myelin sheath that surrounds nerve cells:

b. What is the fatty acid?