Download QUIZ #4 LIPID STRUCTURES AND METABOLISM

QUIZ #4 LIPID STRUCTURES AND METABOLISM
93.
Which of the following is an essential fatty acid?
a. Linoleic
b. Oleic
c. Propionic
d. Lauric
e. Arachidic
94.
What happens to the numbering of an unsaturated fatty acid when its length is increased by elongation?
a. The "delta" number of each carbon increases
b. The "omega" number of each carbon increases
c. Both 1) and 2) are correct
d. Neither 1) nor 2) are correct
95.
If a 20:0 fatty acid is desaturated, elongated and desaturated again, the resulting fatty acid would be:
a. 22:2 delta 11,14
b. 22:2 omega-11
c. 22:2 delta-8,11
d. Both 1) and 2) are correct
e. Both 2) and 3) are correct
96.
What is the basic unit of cholesterol and ß-carotene?
a. Isoprene units
b. Fatty acids
c. Glycerol
d. Methyl-malonyl~CoA
97.
Which of the following saturated acids has the highest melting point?
a. Formic acid
b. Butyric acid
c. Palmitic Acid
d. Arachidic acid
98.
In humans, which fatty acid is a DIRECT precursor for prostaglandin synthesis?
a. 18:2 omega-9
b. 22:6 omega-3
c. 20:4 omega-6
d. 18:2 omega-6
e. 18:3 omega-6
99.
Which of the following is true about cardiolipin?
a. It is found in the inner membrane of mitochondria
b. It consists of 4 fatty acids, 2 phosphates and 2 glycerols
c. Is most similar to the sphingolipids called gangliosides
d. Can only be found in cardiac tissue
e. All of the above are true
100.
Which enzyme is inhibited by cortisol?
a. Prostaglandin synthase
b. Prostaglandin reductase
c. 5-Lipoxygenase
d. Phospholipase A2
e. Phospholipase C
101.
All of the following consist of isoprene units EXCEPT:
a. Vit E
b. CoQ
c. PAF
d. Vit K
e. Dolichols
102.
A fatty acid that is 18:2 is:
a. Linoleic
b. Oleic
c. Palmitic
d. Arachidic
e. Arachidonic
103.
Which of the following is FALSE concerning the insertion of double bonds in a fatty acid by a
desaturase enzyme?
a. Will not desaturate "deeper" than C9 from the COOH end
b. Can form either cis or trans double bonds
c. Second double bond cannot form distal to (from the delta end) to an existing double bond
d. A second double bond is added with a methylene interruption
104.
Which statement regarding lipids is TRUE?
a. Plasmalogens are examples of sphingolipids
b. Phosphatidyl serine can be converted in one step to phosphatidyl choline
c. Phosphatidyl choline is the most abundant membrane phospholipid
d. Phospholipids are randomly associated with the inner and outer layers of membranes
e. Phospholipids are easily "flip-flopped" across membranes
105.
Which of the following enzymes is NOT present in adipocytes?
a. Phosphofructokinase
b. Phosphoglycerate kinase
c. Pyruvate kinase
d. Glycerol kinase
e. Hormone sensitive lipase
106.
Which of the following is NOT associated with ß-oxidation of fatty acids?
a. Uses NAD and FAD
b. Occurs in the mitochondrion of the cell
c. Uses invididual enzymes rather than an enzyme complex
d. Acyl~Carrier Protein is the carrier of the acyl~ group
107.
Which of the following is NOT true of ß-oxidation : fatty acid synthesis?
a. Mitochondrial : Cytosolic
b. acetyl~CoA: malonyl~CoA
c. Hydration : Dehydration
d. Free Enzymes : Enzyme Complex
e. NADPH : FADH2
108.
HMG~CoA redutase is inhibited by:
a. Cholesterol
b. Glucagon
c. Both
d. Neither
109.
Identify the forms of the nucleotides used in ß-oxidation and fatty acid synthesis, respectively.
a. FAD; NADH
b. NADP; NADPH
c. NADPH; FAD
d. FAD; NADPH
e. NAD; NADH
110.
You have two 6-carbon compounds; one is glucose and the other is caproic acid (6:0). If both are
complexely oxidized to CO2 and H2O, what is the ratio of their potential maximum ATPs generated?
a. Glucose yields 38 ATP where as caproic acid yields 28 ATP
b. Glucose yields 28 ATP where as caproic acid yields 38 ATP
c. Glucose yields 36 ATP where as caproic acid yields 38 ATP
d. Glucose yields 38 ATP where as caproic acid yields 44 ATP
e. Glucose yields 38 ATP where as caproic acid yields 46 ATP
111.
Which of the following stimulates HDL synthesis?
a. Lecithin
b. A sedentary lifestyle
c. LCAT and ACAT
d. Moderate alcohol intake
e. Leptin
112.
Which of the following allosterically activates acetyl~CoA carboxylase?
a. Citrate
b. ATP
c. AMP
d. Glucagon
e. Palmityl~CoA
113.
What is the key regulatory enzyme for fatty acid synthesis?
a. Malate Dehdyrogenase
b. Malic Enzyme
c. Citrate Cleavage Enzyme
d. Acetyl~CoA carboxylase
e. Pyruvate Carboxylase
114.
Fatty acid synthesis occurs:
a. In the cytosol
b. On a large enzyme complex
c. Under well-fed conditions
d. Under the positive influence of insulin
e. All of the above are correct
115.
Which of the following statements regarding the regulation of serum cholesterol is FALSE?
a. Ingestion of cholestyramine resin increases cholesterol excretion
b. Cholesterol is degraded to CO2 and H2O
c. HMG~CoA reductase is a membrane bound enzyme
d. Most of our cholesterol is converted into bile salts and acids
e. The carbons in cholesterol can be traced to carbohydrates
116.
Which of the following conversions between phospholipid groups does NOT take place?
a. PE --> PC
b. PC --> PE
c. PS --> PE
d. PA --> PC
e. PC --> Sph
117.
Lecithin plays an important role in the transfer of cholesterol between:
a. Chylomicrons and VLDLs
b. VLDLs and IDLs
c. IDLs and LDLs
d. LDLs and HDL3s
e. LDLs and peripheral tissues
118.
The mobilization of triacylglycerol bound fatty acids from adipose tissue and their subsequent oxidation
by muscle mitochondria require all of the following EXCEPT:
a. serum albumin
b. carnitine
c. acetyl~CoA carboxylase
d. hormone sensitive lipase
e. fatty acyl~CoA synthetase
119.
Apoprotein CII acts to:
120.
a. stimulate lipoprotein lipase
b. activate LCAT
c. facilitate LDL uptake
d. inhibit hormone sensitive lipase
e. convert LDL's into HDL's
What is the function of ApoCII?
a. Activation of the LCAT enzyme
b. Attaches LDL to its receptor
c. Mediates the delivery of cholesterol to peripheral tissues
d. Activation of lipoprotein lipase
e. Inhibition of hormone sensitive lipase
121.
Which of the following enzymes is NOT used in fatty acid synthesis beginning with citrate?
a. kinase
b. reductase
c. dehydratase
d. thiolase
e. lyase
122.
The addition of radioactively labeled 14CO2 to a cell that is actively synthesizing fatty acids will appear
in the final fatty acid product.
a. True
b. False
123.
If acetyl~CoA is 14C radioactively labeled in both of its carbons and it is add to a cell that is actively
synthesizing fatty acids, the radioactivity will appear ________ in the final product.
a. in every carbon
b. in every other carbon
c. only in the two carbons at the omega end
d. in every carbon EXCEPT the two at the omega end
e. only in the two carbons at the delta end
124.
In which form are most lipids transferred out of the intestinal mucosal cells into the lymphatic system?
a. Free fatty acids
b. 2-Monoacyl-glycerols
c. Chylomicrons
d. Micelles
e. Free triglycerides
125.
Which of the following statements is (are) TRUE?
a. HMG~CoA --> mevalonate is the regulatory step in cholesterol biosynthesis
b. Synthesis of cholesterol begins with the condensation of two acetyl~CoA's in the cytosol
c. Glucagon ultimately leads to decreased HMG~CoA reductase activity
d. Cytosolic NADH is a co-substrate for HMG~CoA reductase
a. a), b) and c) are true
b. a) and c) are true
c. b) and d) are true
d. d) only is true
e. all (a-d) are true
126.
Which leucotriene is responsible for smooth muscle contraction during anaphylactic shock?
a. LTA4
b. LTB4
c. LTC4
d. LTD4
e. LTE4
127.
What is the function of ApoB100?
a. activate lipoprotein lipase
b. transport HDL3 out of the liver
c. activates LCAT
d. facilitates the uptake of LDL by peripheral tissues
e. none of the above are correct