Question :
21) A fat or oil becomes rancid when
A) its : 1363027
21) A fat or oil becomes rancid when
A) its double bonds are oxidized.
B) it is hydrogenated.
C) it is hydrolyzed.
D) it is saponified.
E) it is partially hydrogenated.
22) Margarine containing partially hydrogenated soybean oil is solid because
A) it contains only saturated fats.
B) it contains only trans fatty acids.
C) some of its double bonds have been converted to single bonds.
D) it contains only cis double bonds.
E) it contains only polyunsaturated fatty acids.
23) Palmitic acid is a 16 carbon acid. In a balanced equation, the products of the saponification of tripalmitin (glyceryl tripalmitate) are
A) O
||
CH2 – OH + 3 H3C – (CH2)14 – C – OH
|
CH – OH
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CH2- OH
B) O
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CH2- O- Na+ + 3 H3C – (CH2)14 – C- OH
|
CH – O- Na+
|
CH2- O- Na+
C) O
||
CH2 – OH + 3H3C – (CH2)14 – C – O- Na+
|
CHOH
|
CH2 – OH
D) O
||
CH2 – OH + H3C – (CH2)14 – C – O- Na+
|
3 CHOH
|
CH2 – OH
E) O
||
CH2 – OH + 2H3C – (CH2)14 – C – O- Na+
|
CHOH O
| ?
CH2 – OH + H3C – (CH2)16 – C – O- Na+
24) The products of the acid catalyzed hydrolysis of a fat are
A) the esters of fatty acids.
B) fatty acids and glycerol.
C) salts of fatty acids.
D) salts of fatty acids and glycerol.
E) phospholipids.
25) The products of the saponification of a fat are
A) the esters of fatty acids.
B) fatty acids and glycerol.
C) salts of fatty acids.
D) salts of fatty acids and glycerol.
E) phospholipids.
26) A fatty acid salt can act as a soap to remove grease because
A) the nonpolar tails of the salt dissolve in the grease and the polar salt ends dissolve in water.
B) the nonpolar tails of the salt cause the salt to float on the surface of the water.
C) the polar salt ends dissolve in the grease and the nonpolar tails cause the resulting micelles to float on water.
D) the grease molecules form a thin layer around each salt molecule, making them soluble in water.
E) the salt molecules combine with grease and either Ca2+ or Mg2+ to form a precipitate.
27) Glycerolphospholipids can interact both with other lipids and water because they contain both __________ and __________.
A) single bonds; double bonds
B) polar regions; nonpolar regions
C) glycerol; sphingosine
D) saturated fatty acids; unsaturated fatty acids
E) bile salts; cholesterol
28) The components in the following glycerolphospholipid are
A) sphingosine, palmitic acid, phosphate, and choline.
B) sphingosine, palmitic acid, phosphate, and serine.
C) glycerol, palmitic acid, phosphate, and ethanolamine.
D) glycerol, palmitic acid, phosphate, and galactose.
E) sphingosine, palmitic acid, phosphate, and ethanolamine.
29) The main lipid components in cellular membranes are
A) glycerolphospholipids.
B) terpenes.
C) steroids.
D) triacylglycerols.
E) waxes.
30) In the list below, which lipid type is most soluble in water?
A) triacylglycerols
B) glycerophospholipids
C) oils
D) steroids
E) waxes
