1.The basic structure common to steroids contains:
a) Three condensed rings joined together
b) Four condensed rings
c) Five condensed rings
d) Six condensed rings
2.Phospholipase C reacts with phosphatidyl ethan-olamine to release:
a) The fatty acid at C1 of phosphatidyl ethanol-amine
b) The fatty acid at C2 of phosphatidyl ethanol-amine
c) Phosphorylethanolamine
d) Ethanolamine
3.Triglycerides or triacylglycerols belong to which class of lipids?
a) Neutral fats
b) Phospholipids
c) Carotenoids
d) Steroids
e) Cerebrosides
4.The potassium salt of stearic acid is a (an):
a) Ester
b) Ketone
c) acid anhydride
d) Soap
5.The complete hydrogenation of linoleic acid yields:
a) Oleic acid (C 18:1)
b) palmitic acid (C 16:0)
c) Stearic acid (C 18:0)
d) decanoic acid (C 10:0)
6.The fatty acids of animal origin are primarily:
a) short-chain unsaturated dicarboxylic acids
b) branched-chain acids with high molecular weights
c) straight-chain saturated or unsaturated mono-carboxylic acids with an even number of car-bon atoms
d) iong-chain carboxylic acids with an odd num-ber of carbon atoms
7.The essential fatty acids important to human nutrition are:
a) oleic, linoleic and linolenic
b) linoleic, arachidonic and stearic
c) palmitoleic, oleic, and arachidonic
d) arachidonic, linoleic and linolenic
8.At pH 7.0. Which of the following have a positive--negative charge ratio of 1: 1?
a) lecithin. phosphatidyl serine and phosphatidyl ethanolamine
b) lecithin, posphatidyl ethanolamine and phosphatidyl inositol
c) lecithin. phosphatidyl ethanolamine and sphingomyelin
d) lecithin. sphingomyelin and phosphatidyl inositol
9.Hydrolysis of Phosphatidalcholine (plasmalogen) yields phosphorylcholine, glycerol and:
a) a fatty acid and a ketone
b) a fatty acid and an aldehyde
c) a fatty acid and an ether
d) two fatty acids
10.Triacylglycerol hydrolysis by lipase is regulated by:
a) Epinephrine
b) Glucagons
c) cyclic AMP
d) all of the above
11.Insulin diminishes lipolysis in adipocytes by:
a) reducing cell membrane permeability to glu-cos
b) inactivating phosphodiesterase
c) Reducing concentration of cyclic AMP in the cell
d) None of the above
12.Free fatty acids released from adipose tissue by lipase hydrolysis are carried in the blood by:
a) globulins
b) albumin
c) bile salts
d) chylemicrons
13.Fatty and oxidation occurs in:
a) the cyloplasm.
b) the microsems
c) the mitocondria
d) (a) and (b)
e) all of the above
14.Transfer of acyl and acetyl groups into the mito- chondria is facilitated by:
a) coenzyme
b) carnitine
c) biotin
d) acyl carrier proteins
15.The major protein of energy stored in fatty acids is released due to:
a) beta oxidation
b) oxidation of two carbon fragments resulting from beta oxidation
c) there is no difference between the above processes
d) hydrolysis of the acyl CoA bond
16.An enzyme that functions in the beta oxidation pathway is:
a) hexokinase
b) pyruvate
c) triose phosphate isomerase
d) acyl CoA dehydrogenase
e) maltase
17.Which of the following beta oxidation reactions is written incorrectly?
a) acyl CoA+FAO?enoylCoA+FADH
b) enoyl CoA + HzO ? beta hydroxy acyl CoA
c) beta hydroxy acyl CoA + FAO ? ketoacyl
CoA+FADH2
d) ketoacyl CoA + coenzyme A - acyl CoA + acetyl CoA
18.Excess fat utilization such as that occurring 10 diabetes results in the increased production of ketone bodies. Which of the following compounds is not a ketone body?
a) acetone
b) beta hydroxybutyric acid
c) acetoacetic acid
d) alpha ketoglutaric acid
19.An intermediate common to the synthesis of both ketone bodies and cholesterol is:
a) beta hydroxy-beta methyl glutaryl CoA
b) succinyl CoA
c) acetoacetyl CoA
d) mevalonic acid
e) farnesyl phosphate
20. During the conversion of acetyl CoA to cholesterol, one of the following compounds is not an intermediate:
a) malonyl CoA
b) mevalonic acid
c) beta hydroxy-beta methyl glutaryl CoA
d) farnesyl pyrophosphate
21.Feedback inhibition of cholesterol biosynthesis in mammals is controlled during:
a) formation of beta hydroxy-beta methyl glutaryl CoA from acetyl CoA
b) conversion of mevalonic acid to isopentenyl pyrophosphate
c) conversion of beta hydroxy-beta methyl glu taryl CoA to mevalonic acid
d) conversion of isopentenyl pyrophosphate to squalene
22.Cholesterol or one of its derivatives in mammals is metabolized to all but which one of the following?
a) vitamin D
b) steroid hormones
c) bile acids
d) bile pigments
23.The extra mitochondrial synthesis of palmitic acid:
a) requires NADPH as a reductant
b) requires acetyl CoA
c) utilizes nalonyl CoA as an activated donor of
2-corbon fragments
d) requires acyl-carrier protein to covalently link the intermediates of the reaction
e) all of the above
24.Which one of the following vitamins functions as a carbon fragment carrier during the initial step of atty acid biosynthesis?
a) biotin
b) riboflavin
c) thiamine
d) vitamin D
25.One of the following lipids would not become
abeled from C-acetate in humans:
a) cholesterol
b) beta hydroxybutyric acid
c) oleic acid
d) acetone
e) linoleic acid
26.Phosphatidate (Phosphatidic acid) is an inler-
ediate in the synthesis of:
a) triacylglycerol
b) sphingomyelin
c) cholesterol
d.none of the above
27.Synthesis Of phosphalidate starts with formation glycerol-3-phosPhate. Which can be obtained from:
a) the reduction of dihydroxy acetone phosphate by NADH
b) the reduction of 1.3-diphosphoglyceric acid by NADPH
c) the phosphorylation of glycerol by ATP
d) both (a) and (c)
28. A necessary intermediate during conversion of
Posphatidic acid to triacylglycerol is:
a) CDP diglyceride
b) dihydrospingosine
c) monoacylglycerol
d) diacylglycerol
29.During synthesis of phospholipids, both choline ethanolamine are activated through a reaction with:
a) GTP
b) TTP
c) UTP
d) CTP
30.The activated intermediate required during in-
corporation of inositol into phosphatidyl inositol is:
a) ADP inositol
b) UDP inositol
c) CDP diacylglycerol
d) CDP inositol
31.In mammalian systems, phosphatidyl serine is synthesized by which of the following reactions:
a) diacylglycerol + CDP serine- phosphatidyl serine + CMP
b) phosphatidyl ethanolamine + serine ? phosphatidyl serine + ethanolamine
c) phosphatidic acid + serine ? phosphatidyl serine
c) phosphatidic acid + serine ? phosphatidyl serine
32.The liver can synthesize lecithin by the progressive methylation of phosphatidyl ethanolamine. The source of the methyl groups is:
a) N5 methyl tetrahydrofolate
b) S-adenosyl methionine
c) melhyl malonyl CoA
choline
33.Which of the following fatty acids serves as a
metabolic precursor for sphingosine?
a) palmitic acid
b) oleic acid
c) stearic acid
d) arachidonic acid
34.Which of the following substances represents the immediate precursor for fatty acid synthesis?
a. Glucose
b.Citrate
c. Acetyl-CoA
d. Acetoacetate
35.Ingestion of which of the following most markedly affects the rate of gastric emptying?
a. Fats
b. Minerals
c Proteins
d. Carbohydrates
36.Mobilization of fat stored in adipocytes involves
a. activation of fatty acids by synthesis of acyl CoA
b. rearrangement of fatty acids in triglycerides
c.3. phosphorylation of glycerol at the expense of ATP.
5. activation of triglyceride lipase by a CAMP dependent protein kinase.
37.Neutral fats contain mixtures of one or more fatty acids esterified with
a. sterol.
b. glycerol.
c. lecithin.
d. sphingosine.
38.Prostaglandins are made within cells
a. on an RNA template.
b. on rough endoplasmic reticulum.
c. from methionine.
d. from polyunsaturated fatty acids.
39.The major driving force for formation of a lipid micelle is
a. protein-lipid interaction.
b. hydrophobic interaction between hydrocarbon tails.
c. hydrogen bonding between water molecules of the micellar core
d. electrostatic interaction between the micellar core and polar heads
40.A deficiency of choline in the diet may cause abnormalities in metabolism of
a. lipids.
b. proteins.
c. minerals.
d. carbohydrates.
41. Which of the following lipids participates in mitochondrial electron transport?
a. Ubiquinone
b. Beta-karotene
c. Alfa-tocopherol
d. Sphingomyelin
42.The final step in the complete metabolism of fat is carried out by means of
a. anaerobic glycolysis.
b. the tricarboxylic acid cycle
c. the reductive fixation of CO2
d. the hexose monophosphate shunt
43. F ree fatty acids are transported in blood plasma as
a. sodium salts.
b. undissociated acids.
c. a complex with albumin
d. a micelle complexed with bile salts
44.Triglyceride absorbed into the lymphatic system is transported to the liver as
a. chylomicrons.
b. very low density lipoprotein
c. high density lipoprotein
d. very high density lipoprotein
45. The lipotropic effect of lecithin upon fatty livers may also be produced by
a. Choline
b. Lipoic acid
c. Ethanolamine.
d. Beta-hydroxybytyric acid
46.Lipid is required in the average diet because it
a.has a high caloric value.
b. provides essential falty acids.
c.aids in absorption of carbohydrates.
d.is necessary for storage of carbohydrates
47.Upon complete hydrogenation, oleic, linoleic and linolenic acids yield
a.stearic acid.
b.myristic acid.
c. palmitoleic acid.
d.arachidonic acid.
48.Which of the following compounds is an intermediate in the biosynthesis of cholesterol?
a.Squalene
c. cholic acid
b. Hexosamine
d. Pregnanediol
49.The products of hydrolysis of lecithin are
a.glycerol, fatty acids, phosphoric acid, serine.
b. glycerol,fatty acids, phosphoric acid, ,choline.
c.sphingosine, acetic acid; phosphoric acid,inositol.
d. glyceraldehydes, fatty acids, phosphoric acid, choline .
50.Which of the following is an essential fatty acid?
a. Acetic
b. Stearic
c.Myristic
d. Arachildonic