Exam 3 Practice Exams Flashcards
Please select the false statement:
a. Cholesterol is used as a membrane lipid
b. Cholesterol is used precursor to steroid hormones
c. Cholesterol is used as a precursor to bile salts
d. Cholesterol is used as a precursor to phosphatidylinositol
d. Cholesterol is used as a precursor to phosphatidylinositol
Please select the equivalent of: 16:1 cis-∆ 9
a. CH3CH2 CH2 CH2 CH2 CH=CH CH2 CH2 CH2 CH2 CH2 CH2 CH2 CH2 CH2 CH2 COO-
b. CH3CH2 CH2 CH2 CH2 CH2 CH2 CH2 CH2 CH= CH CH2 CH2 CH2 CH2 COO-
c. CH3CH2 CH2 CH2 CH2 CH2 CH2 CH2 CH=CH CH2 CH2 CH2 CH2 COO-
d. CH3CH2 CH2 CH2 CH2 CH2 CH=CH CH2 CH2 CH2 CH2 CH2 CH2 CH2 COO-
e. None of the above are correct
d. CH3CH2 CH2 CH2 CH2 CH2 CH=CH CH2 CH2 CH2 CH2 CH2 CH2 CH2 COO-
Which fatty acid is an omega 6 fatty acid?
a. CH3CH2 CH2 CH2 CH2 CH=CH CH2 CH2 CH2 CH2 CH2 CH2 CH2 CH2 CH2 CH2 COO-
b. CH3CH2 CH2 CH2 CH2 CH2 CH2 CH2 CH2 CH= CH CH2 CH2 CH2 CH2 COO-
c. CH3CH2 CH2 CH2 CH2 CH2 CH2 CH2 CH=CH CH2 CH2 CH2 CH2 COO-
d. CH3CH2 CH2 CH2 CH2 CH2 CH=CH CH2 CH2 CH2 CH2 CH2 CH2 CH2 COO-
e. None of the above are correct
a. CH3CH2 CH2 CH2 CH2 CH=CH CH2 CH2 CH2 CH2 CH2 CH2 CH2 CH2 CH2 CH2 COO-
Please select the true statement:
a. Bile salts are made in the small intestine
b. Bile salts are both polar and non polar
c. Bile salts reduce the ability of lipids to be suspended in aqueous solution.
d. None of the above is true.
b. Bile salts are both polar and non polar
Fats are another term for all lipids, including cholesterol, phospholipids and triacylglycerol.
a. True
b. False
b. False
Please select the true statement:
a. Formation of fatty acyl-Coenzyme A is the first step in cholesterol synthesis.
b. Formation of fatty acyl-Coenzyme A allows β-oxidation of fatty acid chains longer than 8C.
c. Fatty acyl CoA synthesis is required for phosphatidate synthesis
d. Only a and b are true
e. Only b and c are true
e. Only b and c are true
Phosphatidate is a precursor in the synthesis of all except:
a. Ceramide
b. Phospholipids
c. Triacylglycerols
d. Actually, all the above have phosphatidate as a precursor.
a. Ceramide
In a cell that needed only NADPH in large amounts, what numbered pathways would be used?
- Oxidative pentose phosphate pathway, forward
- Non-oxidative pentose phosphate pathway, forward
- Non-oxidative pentose phosphate pathway, backward
- Glycolysis
- Gluconeogenesis
- TCA cycle
- Electron transport chain
a. 1,2, and 5 only
b. 3 only
c. 1 and 2 only
d. 1,2, and 4 only
e. 1,2, 4, 6 and 7 only
f. None of the above
a. 1,2, and 5 only
In a cell that needed only nucleotides, not NADPH, in large amounts, what numbered pathways would be used?
- Oxidative pentose phosphate pathway, forward
- Non-oxidative pentose phosphate pathway, forward
- Non-oxidative pentose phosphate pathway, backward
- Glycolysis
- Gluconeogenesis
- TCA cycle
- Electron transport chain
a. 1,2, and 5 only
b. 3 only
c. 1 and 2 only
d. 1,2, and 4 only
e. 1,2, 4, 6 and 7 only
f. None of the above
b. 3 only
Please select the true statement:
a. The reactions of fatty acid synthesis occur in the mitochondria
b. Acetyl CoA carboxylase is the enzyme that regulates the rate of fatty acid beta-oxidation.
c. The formation of acetyl Co A from malonyl-CoA by decarboxylation is the committed step of fatty acid synthesis.
d. Citrate is a potent activator of fatty acid synthesis.
d. Citrate is a potent activator of fatty acid synthesis.
Inhibition of the electron transport chain by antimycin would have what effect on Complexes I and IV:
a. Both Complex I and IV would be oxidized.
b. Complex I would be reduced, Complex IV would be oxidized.
c. Both Complex I and IV would be reduced.
d. Complex I would be oxidized, Complex IV would be reduced.
e. None at all, their function would not be affected and ATP would still be produced.
b. Complex I would be reduced, Complex IV would be oxidized.
Which would increase glycogen production in the liver?
a. Insulin levels are high.
b. Glycogen phosphorylase is activated by phosphorylation
c. The global effectors, epinephrine and glucagon have bound their receptors to activate second messenger systems
d. None of the above
e. a and b only
a. Insulin levels are high
During fatty acid synthesis, the progression of reactions is (in this order) :
a. Oxidation, reduction, oxidation, thiolysis
b. Condensation, reduction, dehydration, reduction
c. Oxidation, hydration, oxidation, thiolysis
d. None of the above is correct.
b. Condensation, reduction, dehydration, reduction
During fatty acid synthesis, the condensation of an acetyl group is driven forward in part by CO2 release from the three-carbon malonyl group attached to the Acyl Carrier protein, in this way, the human body primarily generates even-numbered fatty acids, added in two carbon units.
a. True
b. False
a. True
Please select the true statement:
a. Local control of glycogen phosphorylase by free glucose in the liver increases the tendency of this enzyme to be in the relaxed state.
b. Glycogen phosphorylase breaks alpha 1,4-glycosidic bonds to release glucose 6-phosphate.
c. Glycogen phosphorylase breaks down alpha 1,6-glycosidic bonds to release free glucose.
d. None of the above is true.
d. None of the above is true.
Please select the true statement:
a. Sphingolipids are a class of membrane lipids found in all tissues, but with highest concentrations the central nervous system.
b. Desaturation of fatty acids occurs in the mitochondrion.
c. Respiratory distress syndrome in premature infants can be caused by insufficient formation of dipalmitoyl phosphatidylcholine.
d. Only a and c are true.
e. None of the above is true
d. Only a and c are true.
Please select the true statement:
a. Favism results from a mutation in glycogen synthase, and although it is usually subclinical, its symptoms are seen when the patient eats fava beans in sufficient quantities.
b. Mutations in glucose 6-phosphate dehydrogenase can result in hemolytic anemia.
c. NADPH is necessary in red blood cells to oxidize glutathione.
d. Only a and b are correct
e. Only a and c are correct
f. None of the above is correct.
b. Mutations in glucose 6-phosphate dehydrogenase can result in hemolytic anemia.
The main product of fatty acid synthase is the 16-carbon fatty acid, palmitate.
a. True
b. False
a. True
The human body cannot break down odd-numbered fatty acids.
a. True
b. False
b. False
When the malate aspartate shuttle is used, reducing equivalents enter the mitochondrial matrix as:
a. Oxaloacetate
b. Malate
c. Alpha-ketoglutarate
d. Aspartate
e. FADH2
b. Malate
Methylmalonyl CoA mutase catalyzes an intramolecular rearrangement that requires vitamin B12, (cobalamin) and produces succinyl CoA.
a. True
b. False
a. True
Please select the true statement:
a. Malonyl Co A is formed as an activated intermediate for cholesterol synthesis.
b. Geranyl pyrophosphate is a 5-carbon intermediate of cholesterol synthesis.
c. Farnesyl pyrophosphate is an intermediate derived from 2 activated isoprene units and is a 10C
d. Synthesis of one molecule of 3-isopentyl pyrophosphate requires HMG CoA (3-hydroxy,3-methylglutaryl CoA), and 3 molecules of ATP.
d. Synthesis of one molecule of 3-isopentyl pyrophosphate requires HMG CoA (3-hydroxy,3-methylglutaryl CoA), and 3 molecules of ATP.
Please select the true statement:
a. VLDLs are apolipoproteins formed in the liver and they contain only triacylglycerol.
b. The primary lipid in chylomicrons is cholesterol.
c. VLDLs contain triacylglycerol of dietary origin.
d. Chylomicron remnants carry dietary lipids to the liver.
d. Chylomicron remnants carry dietary lipids to the liver.
Please select the true statement:
a. Apoprotein B100 is found in in circulating VLDLs.
b. Apoprotein B48 is found in in circulating LDLs.
c. Apoprotein CII activates lipoprotein lipase.
d. All of the above are true.
e. Only a and c are true.
f. Only b and c are true.
e. Only a and c are true.
HDLs can transport cholesterol from foam cells to the liver.
a. True
b. False
a. True
Hydration of the double bond in fumarate yields which of the following intermediates?
a. Oxaloacetate
b. Malate
c. Succinate
d. Alpha-ketoglutarate
b. Malate
Is the reaction that generates ATP or GTP during the TCA cycle reversible?
a. yes
b. no
a. yes
High citrate levels are primarily generated when the body is fasting.
a. True
b. False
b. False
Acetyl groups are intermediates in the synthesis of:
a. Fatty acids
b. Cholesterol
c. Glucose
d. All the above.
e. Only a and b
e. Only a and b
If heme synthesis was high, and the only input to the TCA cycle was acetyl-CoA, the cycle eventually be forced to stop
a. True
b. False.
a. True
Please list, in forward direction of the cycle, the enzyme in the TCA cycle that comes immediately after Isocitrate dehydrogenase
Alpha-ketoglutarate dehydrogenase
What are the products of isocitrate dehydrogenase?
Alpha-ketoglutarate, NADH, H+, and CO2
Please list, in forward direction of the cycle, the enzyme in the TCA cycle that comes immediately after Succinate dehydrogenase.
Fumarase
What are the products of succinate dehydrogenase?
Fumarate, FADH2
Please list, in forward direction of the cycle, the enzyme in the TCA cycle that comes immediately after Citrate synthase
Aconitase
Which enzyme in the TCA cycle synthesizes (GTP or ATP?)
Succinyl CoA synthetase
In the Citric acid cycle one molecule of nucleotide monophosphate, either ATP or GTP, is made in one “turn of the cycle”. What else is true of this cycle?
a. 2 molecules of NADH and 1 molecule of FADH2 are produced for each turn of this cycle.
b. The enzyme α-ketoglutarate dehydrogenase catalyzes production of succinate.
c. 2 molecules of CO2 are produced for each turn of this cycle.
d. The enzyme isocitrate dehydrogenase catalyzes production of isocitrate.
c. 2 molecules of CO2 are produced for each turn of this cycle.
The main objects of the TCA cycle are making metabolites that are building blocks for synthetic reactions, and making reducing equivalents that can be used during the process of oxidative phosphorylation to produce ATP.
a. True
b. False
a. True
For every mole of glucose that proceeds through glycolysis to the TCA cycle, how many moles of ATP are made?
a. Four
b. Two
c. 30 if the malate – aspartate shuttle is used.
d. 32 if the malate – aspartate shuttle is used.
e. 36 if the malate – aspartate shuttle is used.
f. 38 if the malate – aspartate shuttle is used.
d. 32 if the malate – aspartate shuttle is used.
Please select the true statement regarding electron transfer:
a. FADH2 produced by the glycerol 3-phosphate shuttle directly reduces complex II.
b. NADH and FADH2 each have a P/O ratio of 2.5
c. Electrons from Complex I directly reduce Complex II
d. Electrons from Cytochrome c(reduced) directly reduce Complex IV
d. Electrons from Cytochrome c(reduced) directly reduce Complex IV
The TCA cycle takes place in both the cytoplasm and in the mitochondrion.
a. True
b. False
b. False
Please choose from the options below to make this a true statement: The last three reactions of the TCA cycle are…
a. similar to the progression of reactions in beta-oxidation.
b. catalyzed by succinyl CoA synthetase, succinate dehydrogenase, and fumarase,
c. directly responsible for production of 2 moles of NADH for each round of the cycle. .
d. Only a and b truthfully complete the sentence.
e. Only b and c truthfully complete the sentence.
a. similar to the progression of reactions in beta-oxidation.
What effect do glucagon and epinephrine have on fatty acid synthesis?
a. These global signals decrease the rate of fatty acid synthesis.
b. These local signals decrease the rate of fatty acid synthesis.
c. These global signals increase the rate of fatty acid synthesis.
d. These local signals increase the rate of fatty acid synthesis.
a. These global signals decrease the rate of fatty acid synthesis.
HMG Co A Reductase is an integral membrane protein that catalyzes the first committed step in cholesterol synthesis.
a. True
b. False
b. False
Please chose the false statement:
a. The carrier of acyl groups during fatty acid synthesis is the acyl carrier protein and a cysteine within fatty acid synthase itself.
b. Fatty acid synthase catalyzes both the formation of fatty acids, and their desaturation.
c. Fatty acid synthesis is inhibited by it product, palmitate
d. The maximum length of a fatty acid made by fatty acid synthase alone is 16 carbons.
b. Fatty acid synthase catalyzes both the formation of fatty acids, and their desaturation.
Please chose the false statement regarding the catabolism of odd-numbered fatty acids:
a. Propionyl CoA is converted to an intermediate of the TCA cycle, succinyl CoA.
b. This catabolism requires vitamin B12 derivative, tetrahydrofolate.
c. During this catabolism, propionyl CoA is converted to methylmalonyl CoA in an ATP-dependent carboxylation, that requires biotin.
d. Cobalt is a cofactor required for free radical generation during this catabolism.
b. This catabolism requires vitamin B12 derivative, tetrahydrofolate.
Please chose the true statement:
a. H2O is added in trans across the double bond of fumarate to yield L-Malate.
b. Catabolism of fatty acids occurs in both the mitochondrial matrix and peroxisomes in mammals.
c. Acetyl CoA cannot pass through inner mitochondrial membrane.
d. All of the above are true.
e. Only a and b are true.
d. All of the above are true.
Please chose the true progression of reactions in fatty acid synthesis, beginning to end:
a. Oxidation, Hydration, Oxidation, Thiolysis
b. Thiolysis, Oxidation, Hydration, Oxidation
c. Condensation, Reduction, Dehydration, Reduction
d. Condensation Dehydration, Reduction, Dehydration
c. Condensation, Reduction, Dehydration, Reduction
Ketone bodies are derivatives of acetyl CoA, used for energy production in heart and are also used in the brain when carbohydrates stores are low or glucose metabolism is impaired.
a. True
b. False
a. True
What effect does phosphorylation have on the following? Please choose the correct effect.
a. Glycogen phosphorylase activity decreases when this enzyme is phosphorylated.
b. Acetyl CoA carboxylase activity increases when this enzyme is phosphorylated.
c. Glycogen synthase activity increases when this enzyme is phosphorylated.
d. Glycogen phosphorylase kinase activity increases when this enzyme is phosphorylated.
e. Only b, c, and d are true.
f. Only a and d are true.
d. Glycogen phosphorylase kinase activity increases when this enzyme is phosphorylated.
Which of these pathways occurs in the mitochondrion?
a. Cholesterol synthesis
b. Glycogen synthesis
c. Fatty acid synthesis
d. None of these occur in the mitochondrion.
e. Each of these pathways occurs in the mitochondrion.
d. None of these occur in the mitochondrion.
What is true of the fatty acid shown here:
CH3-CH2-CH=CH-CH2-CH2- CH2-CH2- CH2-CH2-CH2-COOH
a. It is noted as 12:1∆9
b. It is an omega 9 fatty acid
c. It is noted as 12:1∆3
d. It is noted as 12:9∆3
e. Only a and b are true.
a. It is noted as 12:1∆9
Please choose the true statement:
a. Glycogen synthesis requires glucose 1-P as an activated synthetic activated precursor.
b. Glycogenin is a necessary primer molecule for initiating synthesis of a new glycogen macromolecule.
c. Straight chains of glycogen have an α-1,6 linkage
d. Glycogen branch points have an α-1,4 linkage.
e. All the above are true.
f. Only a and d are true.
b. Glycogenin is a necessary primer molecule for initiating synthesis of a new glycogen macromolecule.
Please select the true statement:
a. Tay-Sachs is a fatal neurodegenerative condition caused by a failure in dipalmitoyl phosphatidylcholine formation.
b. The enzyme, β-N-acetylhexosaminidase, produces a vital component of the surfactant that coats the lung surface, and is deficient in infants with respiratory distress syndrome.
c. Neither a nor b is true.
d. Both a and b are true.
c. Neither a nor b is true.
Please select the true statement:
a. The most common fatty acids in mammals are 20 carbons in length.
b. The fatty acids in archea membrane lipids are generally branched.
c. The double bonds in mammalian fatty acids are in the trans configuration.
d. Polyunsaturated double bonds in mammalian fatty acids are generally separated by 4 C.
b. The fatty acids in archea membrane lipids are generally branched.
α-ketoglutarate dehydrogenase is inhibited by high cellular concentrations of succinyl CoA.
a. True
b. False
a. True
Please select the true statement:
a. Phosphatidate is an activated intermediate in triacylglycerol synthesis and in the synthesis of glycerophospholipids.
b. Glycerol phosphate acyltransferase catalyzes synthesis of phosphatidate from pyruvate.
c. Phospholipids are made up of one or more fatty acids linked to a glycerol or sphingosine backbone, and also contain a phosphate group to which is linked an alcohol head group.
d. All the above are true.
e. Only a and c are true.
e. Only a and c are true.
Please select the true statement regarding bile salts:
a. Bile salts are derivatives of cholesterol and are less polar in nature than cholesterol.
b. Bile salts are synthesized in the gall bladder
c. Bile salts are released into the stomach
d. The main role of bile salts is to emulsify triacylglycerols.
d. The main role of bile salts is to emulsify triacylglycerols.
Please select the true statement:
a. Chylomicrons are the least dense of any lipoprotein particle.
b. Chylomicrons contain mostly triacylglycerols of endogenous origin.
c. VLDLs contain mostly cholesterol and cholesterol esters.
d. HDLs are chiefly responsible for delivering cholesterol to the peripheral tissues.
a. Chylomicrons are the least dense of any lipoprotein particle.
Please select the true statement:
a. Apolipoprotein B100 is the primary apolipoprotein found on circulating chylomicrons.
b. The chief function of apolipoprotein CII is to bind LDL receptors and facilitate endocytosis of the receptor-bound LDL particle.
c. VLDLs are formed from LDLs.
d. LDLs can slip between endothelial cells lining blood vessels and cause inflammation.
d. LDLs can slip between endothelial cells lining blood vessels and cause inflammation.
Which of the following is false regarding regulation of fatty acid synthesis:
a. Citrate is an allosteric activator of acetyl-CoA carboxylase as it enhances formation of the active acetyl-CoA carboxylase fiber.
b. Glucagon and epinephrine have an inhibitory effect on fatty acid synthesis.
c. Palmitate promotes citrate export from the mitochondrial matrix
d. Citrate activates acetyl-CoA carboxylase regardless of the phosphorylation state of this enzyme.
c. Palmitate promotes citrate export from the mitochondrial matrix
Please select the true statement:
a. Two moles of NADPH are consumed in the oxidative pentose phosphate pathway.
b. The rate-limiting step of the oxidative pentose phosphate pathway is catalyzed by glucose 6-phosphate dehydrogenase.
c. If the cell needs ribose 5-P for nucleotide synthesis, but not NADPH, only the oxidative portion of the pentose phosphate pathway will be used.
d. If the cell needs large quantities of NADPH but not ATP or nucleotides, only the oxidative portion of the pentose phosphate pathway will be used.
b. The rate-limiting step of the oxidative pentose phosphate pathway is catalyzed by glucose 6-phosphate dehydrogenase.
Oxygen is the final electron acceptor in the electron transport chain.
a. True
b. False
a. True
the intermediate formed by Acetyl CoA and oxaloacetate
citrate
The intermediate after citrate in the TCA cycle
isocitrate
The intermediate after isocitrate in the TCA cycle
Alpha-ketoglutarate, CO2, NADH and H+
The intermediate after alpha-ketoglutarate in the TCA cycle
Succinyl CoA, CO2, NADH, and H+
The intermediate after succinyl CoA in the TCA cycle
Succinate, ATP (or GTP), and CoA
Which component of the oxidative phosphorylation pathway is poisoned by antimycin?
Complex III
If this complex were poisoned by antimycin, would Cytochrome c be found in the oxidized or reduced state?
Oxidized
Which steroid hormone acts on the kidneys to regulate blood pressure and blood volume?
Mineralcorticosteroid
What is the mechanism by which uncouplers of the oxidative phosphorylation pathway function?
Uncouplers provide another way for H+ to move from the mitochondrial intermediate membrane space to the mitochondrial matrix and bypass ATP synthase. This reduces the chemiosmotic gradient without production of ATP. Energy from the chemiosmotic force is transformed to hear in this process.
Palmitate promotes citrate export from the mitochondrial matrix.
a. True
b. False
b. False
Please choose the true statement:
a. Linolenic acid is an essential fatty acid
b. Aldosterone is a precursor for all other steroid hormones
c. Glucocorticosteroid decreases blood glucose levels, and has pro-inflammatory effects
d. Cortisol increases blood volume, and blood pressure.
a. Linolenic acid is an essential fatty acid
Please select the True statement:
a. The TCA cycle is a pathway that takes place in the cytosol.
b. The TCA cycle produces 2 molecules of FADH2 and 1 molecule of NADH for every turn of the cycle.
c. The TCA cycle is inhibited by low ATP concentration.
d. Intermediates in the TCA cycle are replenished through anapleurotic reactions
d. Intermediates in the TCA cycle are replenished through anapleurotic reactions
When the TCA cycle is proceeding in the forward direction, which trio of intermediates is listed in the correct order, with no gaps?
a. Alpha-ketoglutarate, succinate, succinyl CoA
b. Isocitrate, Succinyl CoA, Fumarate
c. Succinyl CoA, Succinate, Fumarate
d. Succinyl CoA, Fumarate, Malate
c. Succinyl CoA, Succinate, Fumarate
The α-ketoglutarate dehydrogenase complex requires the cofactor Thiamine Pyrophosphate.
a. True
b. False
a. True
Which statement correctly describes the movement of reducing equivalents across the inner mitochondrial membrane?
a. The glycerol phosphate shuttle reduces dihydroxyacetone phosphate (DHAP) to form glycerol 3-phosphate and NAD+.
b. The malate-aspartate shuttle reduces oxaloacetate to form malate and FADH2.
c. The glycerol phosphate shuttle oxidizes DHAP to form glycerol 3-phosphate and NAD+.
d. The malate-aspartate shuttle moves oxaloacetate out of the mitochondrial matrix.
e. The malate-aspartate shuttle oxidizes oxaloacetate to form malate and FADH2.
a. The glycerol phosphate shuttle reduces dihydroxyacetone phosphate (DHAP) to form glycerol 3-phosphate and NAD+.
Which poison is correctly paired?
a. Antimycin – Complex IV
b. CO – Complex I
c. Amytal – Complex II
d. Azide –Complex IV
e. Oligomycin –Complex III
d. Azide –Complex IV
Please choose the false statement:
a. Ubiquinone is lipid-soluble electron carrier.
b. Complex II is oxidized by FAD
c. Cytochrome C reduces Complex IV
d. Ubiquinone is reduced by Complex II
b. Complex II is oxidized by FAD
The ultimate electron acceptor in the electron transport chain is:
a. FAD
b. ½ O2 c. NAD+
d. H2O
e. ATP-synthase
b. ½ O2
Please choose the true statement:
a. Chylomicrons are assembled in the liver, and contain apoB-48.
b. VLDL are assembled by the liver, and contain apoB-100.
c. The lipid content of LDL is primarily triacylglycerol.
d. The primary function of apo C II is to promote endocytosis of LDL particles by the liver
b. VLDL are assembled by the liver, and contain apoB-100
Please choose the true statement:
a. Mammals can use acetyl CoA for net conversion to glucose.
b. Thermogenin is a poison of ubiquinone.
c. Oxaloacetate is an intermediate in the synthesis of aspartate, other amino acids, and nucleotides.
d. Glucagon is a hormone released from the liver in response to low serum glucose levels
c. Oxaloacetate is an intermediate in the synthesis of aspartate, other amino acids, and nucleotides.
During fatty acid synthesis, citrate acts an allosteric activator of acetyl CoA carboxylase, as it enhances the formation of the active acetyl CoA carboxylase polymer.
a. True
b. False
a. True
Please choose the true statement:
a. Cholesterol is a sterol that is made even more hydrophobic during production of bile salts.
b. Ceramide is a sphingolipid intermediate used to make cerebrosides and sphingomyelin.
c. Phospholipids like phosphatidyl ethanolamine have a phosphate sugar head group.
d. Synthesis of phospholipids requires UTP and is driven forward by PPi hydrolysis.
b. Ceramide is a sphingolipid intermediate used to make cerebrosides and sphingomyelin.
The committed step in cholesterol synthesis…
a. …occurs in the mitochondrion.
b. …requires ATP.
c. …requires NADPH
d. …results in production of HMG CoA (3-hydroxy-3-methylglutaryl CoA)
e. a and d only.
f. c and d only
c. …requires NADPH
Please choose the listing of 3 intermediates in cholesterol synthesis ordered correctly, with no gaps.
a. geranyl pyrophosphate, farnesyl pyrophosphate
b. HMG CoA, isopentyl pyrophosphate, isoprene
c. Geranyl pyrophosphate, squalene, isoprene
d. Isoprene, geranyl pyrophosphate, squalene
a. geranyl pyrophosphate, farnesyl pyrophosphate
Please choose the true statement:
a. Glycogen phosphorylase a is less active than glycogen phosphorylase b
b. Glycogen phosphorylase a is phosphorylated, while glycogen phosphorylase b is not phosphorylated.
c. Glucagon promotes glycogen synthesis.
d. Glycogen phosphorylase is activated as part of a second messenger cascade activated by insulin.
e. Both c and d are correct.
b. Glycogen phosphorylase a is phosphorylated, while glycogen phosphorylase b is not phosphorylated.
Please choose the true statement:
a. When only ribose is needed, only the oxidative pentose phosphate pathway will be active.
b. When only high amounts of NADPH are needed, only the oxidative pentose phosphate pathway will be active.
c. Glutathione oxidation requires NADPH.
d. Red blood cells are especially sensitive to glucose 6-phosphate dehydrogenase deficiency.
e. Only c and d are true
f. Only a and d are true.
d. Red blood cells are especially sensitive to glucose 6-phosphate dehydrogenase deficiency.
Glycogen phosphorylase releases free glucose directly from straight chains of glycogen.
a. True
b. False
b. False
Glycogen is synthesized when:
a. insulin levels are low
b. glycogen phosphorylase and glycogen synthase are dephosphorylated.
c. stimulated in response to the global effectors, epinephrine and glucagon
d. Only a and b are true.
b. glycogen phosphorylase and glycogen synthase are dephosphorylated.
What is the product of acetyl CoA carboxylase?
a. Acetyl Co A
b. Malonyl Co A
c. Citrate
d. Oxaloacetate
e. Pyruvate
b. Malonyl Co A
Identify the component of oxidative phosphorylation that is poisoned by the following:
Amytal
Complex I
Identify the component of oxidative phosphorylation that is poisoned by the following:
CO
Complex IV
What pathology is associated with the following:
Glucose 6-phosphate dehydrogenase deficiency
Favism, Hemolytic anemia
What pathology is associated with the following: β-N-acetylhexosaminidase
Tay-Sachs Disease
If the electron transport chain were poisoned with antimycin, what
would the oxidation state of the following carriers be, oxidized or reduced?
Ubiquinone
Reduced
If the electron transport chain were poisoned with antimycin, what
would the oxidation state of the following carriers be, oxidized or reduced?
Cytochrome C
Oxidized
Besides a glycogen chain with one less glucosyl residue, please name the immediate product of glycogen phosphorylase.
Glucose 1-P
Please choose the True statement:
a. The TCA cycle produces 3 molecules of NADH for every acetyl CoA group that enters the cycle.
b. The TCA cycle takes place in the cytosol.
c. Three-carbon Acetyl Co A condenses with 3C citrate to produce the 6C intermediate, isocitrate.
d. The intermediate, fumarate is hydrated through a reaction catalyzed by fumarase to make the intermediate malate.
e. All the above are true.
f. Only a and d are true.
f. Only a and d are true.
Please choose the True statement:
a. Two molecules of CO2 are produced by TCA cycle for every acetyl CoA group that enters the cycle.
b. The overall rate of catalysis in the TCA cycle is up‐regulated by high levels of ATP.
c. The rate of the TCA cycle is influenced primarily through regulation of the enzyme malate dehydrogenase.
d. Only a and b are true
a. Two molecules of CO2 are produced by TCA cycle for every acetyl CoA group that enters the cycle.
The alpha-ketoglutarate dehydrogenase enzyme complex requires several cofactors, which include: Coenzyme A, NAD+, and FAD.
a. True
b. False
a. True
Please choose the True statement regarding the use of TCA intermediates in other pathways:
a. Oxaloacetate is used to produce nucleotides and some amino acids.
b. Succinyl CoA is used in heme synthesis.
c. Alpha-ketoglutarate is used to produce amino acids and nucleotides.
d. All the above are true
e. Only a and c are true.
d. All the above are true
Mammals use acetyl CoA to make which of the following:
a. Fatty acids, steroids, glucose and citrate
b. Fatty acids, glucose, citrate and ketone bodies
c. Fatty acids and citrate only
d. Fatty acids, citrate, ketone bodies and steroids
d. Fatty acids, citrate, ketone bodies and steroids
Ubiquinol is formed when ubiquinone accepts electrons from Complex III
a. True
b. False
b. False
If mitochondria were poisoned by addition of cyanide, which of the following would be true:
a. Complex III would be poisoned directly.
b. Complex II would be poisoned directly.
c. Complex I would be poisoned directly.
d. Complex IV would be poisoned directly.
d. Complex IV would be poisoned directly.
Please choose the True statement:
a. Fatty acids are synthesized in the mitochondrial matrix.
b. Citrate is an inhibitor of fatty acid synthesis
c. Production of acetyl CoA is the first committed step in fatty acid synthesis.
d. There are no true answers here.
d. There are no true answers here.
In order, reactions of fatty acid synthesis are: condensation, oxidation, hydration, oxidation.
a. True
b. False
b. False
Phosphorylase a, which is used in glycogen metabolism, is less active than phosphorylase b.
a. True
b. False
b. False
Please choose the false statement:
a. De novo glycogen synthesis requires the primer, glycogenin.
b. Glucose-6 phosphate is released from glycogen branchpoints by the debranching enzyme.
c. Glucagon binding to its receptor results in downstream activation of adenylyl cyclase.
d. Glucagon is a hormone produced in the pancreas.
b. Glucose-6 phosphate is released from glycogen branchpoints by the debranching enzyme.
Please choose the true statement:
a. Sphingolipids, glycolipids, phospholipids and cholesterol are all used as membrane lipids.
b. Cholesterol is used as a synthetic precursor of NAD+
c. Cholesterol esters have a Coenzyme A attached to the hydroxyl group
d. Biosynthesis of cholesterol occurs in the mitochondrion.
a. Sphingolipids, glycolipids, phospholipids and cholesterol are all used as membrane lipids.
Please choose the false statement:
a. Apolipoprotein B-48 is only made in the small intestine.
b. In individuals homozygous for familial hypercholesterolemia, too much LDL remains in the blood.
c. LDL receptor synthesis is regulated by cholesterol levels, such that high serum cholesterol results in an increase in LDL receptor synthesis.
d. The lipids in LDL particles are mainly comprised of cholesterol and cholesterol esters
c. LDL receptor synthesis is regulated by cholesterol levels, such that high serum cholesterol results in an increase in LDL receptor synthesis.
Please choose the true statement:
a. VLDL are formed in the liver and the lipids contained in them are mostly triacylglycerols of dietary origin.
b. HMG-CoA reductase catalyzes the rate-limiting step in cholesterol synthesis.
c. Glucocorticosteroids are derivatives of arachadonic acid.
d. Bile salts are made primarily from fatty acids and are used to emulsify dietary lipids
b. HMG-CoA reductase catalyzes the rate-limiting step in cholesterol synthesis.
Please choose the true statement:
a. Isopentenyl pyrophosphate is made when AMP levels in the cell are high.
b. In a series of reactions during cholesterol synthesis, 3 Molecules of ATP are used to make isopentenyl pyrophosphate.
c. Squalene is a 10-carbon intermediate used in cholesterol synthesis.
d. Oxidoreductase cyclizes lanosterol to make farnesyl pyrophosphate
b. In a series of reactions during cholesterol synthesis, 3 Molecules of ATP are used to make isopentenyl pyrophosphate.
Please choose the true statement:
a. Acetyl CoA carboxylase catalyzes the committed step in fatty acid beta-oxidation.
b. NADPH reduces substrates in the reductive synthetic reactions of fatty acid beta-oxidation.
c. NADPH is produced in the non-oxidative pentose phosphate pathway.
d. Glutathione is important for reducing peroxides and other reactive oxygen species.
d. Glutathione is important for reducing peroxides and other reactive oxygen species.
Glucose 6-Phosphate dehydrogenase catalyzes the first committed step of the oxidative pentose phosphate pathway.
a. True
b. False
a. True
Rapidly dividing cells that need ribose 5-P for nucleotide synthesis but not NADPH, would use the oxidative pathway only and would not use the non-oxidative pentose pathway.
a. True
b. False
b. False
Deficiency of glucose 6-phosphate dehydrogenase is often sub-clinical and becomes noticeable when a person has hemolytic anemia after oxidative challenge that can be a result of:
a. Antibiotics
b. Anitmalarials
c. Infection
d. Eating certain foods like fava beans
e. All of the above
e. All of the above
During β-oxidation of odd-numbered fatty acids, propionyl-CoA is catabolized to succinyl CoA in a series of reactions that require Vitamin B12.
a. True
b. False
a. True
Isoprene units are used for the construction of all of the following EXCEPT:
a. Membrane lipids in archaea
b. Sphingomyelin in eukaryotes
c. Cholesterol
d. Lipid anchors for membrane proteins
b. Sphingomyelin in eukaryotes
Please choose the true statement regarding phosphatidate. Phosphatidate…
a. is an intermediate in cholesterol synthesis.
b. is an intermediate in sphingolipid synthesis.
c. is an intermediate in the synthesis of triacylglycerol.
d. All of the above are true.
c. is an intermediate in the synthesis of triacylglycerol.
Dipalmitoyl phosphatidylcholine can be deficient in preterm infants and lead to respiratory distress.
a. True
b. False
a. True
Please choose the false answer regarding the response of liver cells to glucagon: Glucagon promotes an …
a. increase in the activity of glycogen synthase
b. increase in the activity of glycogen phosphorylase kinase
c. increase in the release of free glucose
d. increase in the intracellular concentrations of cAMP
a. increase in the activity of glycogen synthase
Chylomicrons are produced in the liver and contain more triacylglycerol than cholesterol or cholesterol
esters.
a. True
b. False
b. False
Triacylglycerol must be catabolized to monoacylglycerol and two fatty acids to pass through the cell
membrane and enter cells.
a. True
b. False
a. True
In which of the following processes can glycerol be used as an intermediate?
a. Triacylglycerol synthesis
b. Glycolysis
c. Phospholipid synthesis
d. Gluconeogenesis
e. All the above
f. All but d
e. All the above
Triacylglycerol yields a greater quantity of ATP per gram than glycogen.
a. True
b. False
a. True
Linolenate and linoleate are polyunsaturated essential fatty acids that must be obtained from the diet.
a. True
b. False
a. True
Please choose the true statement:
a. Long saturated fatty acids have lower melting temperatures than shorter unsaturated fatty acids.
b. Humans synthesize odd numbered fatty acids.
c. Humans synthesize unsaturated fatty acids in which double bonds are in the trans configuration.
d. 16 and 18 carbon fatty acids are the most common fatty acids made in animals.
d. 16 and 18 carbon fatty acids are the most common fatty acids made in animals.
please write out the reaction, including the reactants, products and enzyme for the following:
the first committed step of fatty acid synthesis
Acetyl CoA + CO2 (as HCO2-) Yields Malonyl CoA + ADP + Pi + H+
please write out the reaction, including the reactants, products and enzyme for the following:
The forward reaction of the TCA cycle in which succinate is a reactant; don’t forget the electron carrier.
Succinate + FAD Yields Fumarate +FADH2
Please list all of the enzymes that catalyze reactions in which NADH or FADH2 are produced in the TCA cycle
Isocitrate dehydrogenase
Alpha-ketoglutarate
Succinate dehydrogenase
Malate dehydrogenase
In the malate-aspartate shuttle, what is the fate of the oxaloacetate that is made in the mitochondrion? Please choose from: oxidation, reduction, transamination, hydrolysis, hydration.
Transamination
Please write this reaction out including all reactants, products, and the enzyme catalyst (in the mitochondrion):
Oxaloacetate + Gluatmate Yields Alpha-Ketoglutarate + Aspartate
How many NADH are produced by beta-oxidation of a 18-carbon saturated fatty acid?
8
β-N-acetylhexoseminidase is defective or absent in children with a fatal, neurodegenerative disease that is caused by a recessive genetic mutation. What is this disease?
Tay-Sach’s Disease
In a cell that required a great deal of energy and fatty acid synthesis, which of the pathways, i-v, would be active in addition to fatty acid synthesis?
i. Oxidative reactions of the pentose phosphate pathway.
ii. Glycolysis
iii. Non-oxidative reactions of the pentose phosphate pathway
iv. The TCA cycle and oxidative phosphorylation.
v. Gluconeogenesis
a. i, ii, iv
b. i ii, iii, iv
c. i, iv, v
d. iii, iv,v
b. i ii, iii, iv
Which pathways, i or iii, would be active in rapidly dividing cells, like tumor cells, which require nucleic acids for DNA synthesis?
i. Oxidative reactions of the pentose phosphate pathway.
ii. Glycolysis
iii. Non-oxidative reactions of the pentose phosphate pathway
iv. The TCA cycle and oxidative phosphorylation.
v. Gluconeogenesis
a. i
b. iii
c. Both i and iii
b. iii. Fructose 6-P will be used and the non-oxidative PPP will be driven backwards
The committed step in the conversion of glucose-6-phosphate to ribose-5-phosphate is catalyzed by glucose-6-phosphate dehydrogenase.
a. True
b. False
a. True
The cofactor thiamine pyrophosphate serves what purpose?
a. acyl transferase reactions, in which the TPP carbanion makes a nucleophilic attack on the acyl group to be transferred
b. methylation and 1-carbon transfers
c. mutase reactions, in which the cobalt metal is reduced during radical formation
d. epimerization reactions in which the carbocation dissipates the negative charge forming in the transition state.
a. acyl transferase reactions, in which the TPP carbanion makes a nucleophilic attack on the acyl group to be transferred
During ATP synthesis, a proton gradient is used to protonate an aspartate residue in the c-ring of Fo.
a. True
b. False
a. True
Glycogen is synthesized when:
a. insulin levels are low
b. glycogen phosphorylase is deactivated by dephosphorylation
c. in response to the global effectors, epinephrine and glucagon
d. None of the above
b. glycogen phosphorylase is deactivated by dephosphorylation
The oxidative portion of the pentose phosphate pathway produces 3, 4, 5, 6 and 7 carbon sugars.
a. True
b. False
b. False
This occurs in the non-oxidative PPP
Ketone bodies are:
a. derivatives of Acetyl CoA used for energy production in heart muscle and also are used in the brain when carbohydrates stores are low or glucose metabolism is impaired
b. macromolecular assemblages of lipids and lipoproteins used for lipid transport in the blood
c. carbonyl-rich molecules stored in the liver as an alternative to triglycerides when fatty acid anabolism is not fully functional
d. specialized carbohydrate complexes that are accumulated in diabetics instead of glycogen
a. derivatives of Acetyl CoA used for energy production in heart muscle and also are used in the brain when carbohydrates stores are low or glucose metabolism is impaired
The pentose phosphate pathway is:
a. the source of ribose 5-phosphate for nucleotide synthesis
b. the primary source of NADH for anabolic pathways
c. the primary source of NADP+ for anabolic pathways
d. a major source of ATP under dietary carbohydrate limitation
a. the source of ribose 5-phosphate for nucleotide synthesis
Odd carbon fatty acids produce propionyl-CoA, rather than the 2 carbon units, acetyl-CoA, with each turn of the beta oxidation cycle.
a. True
b. False
b. False
In diabetics, excess oxaloacetate is metabolized to ketone bodies.
a. True
b. False
b. False
There is no excess OAA
Which of the following is false regarding regulation of fatty acid synthesis:
a. Citrate is an allosteric activator of acetyl-CoA carboxylase by enhancing the formation of the active polymer
b. Palmitate can reverse the activation by citrate, by promoting acetyl-CoA carboxylase fiber disassembly.
c. Palmitate promotes citrate export from the mitochondrial matrix
d. Citrate activates both phosphorylated and non-phosphorylated acetyl-CoA carboxylase
c. Palmitate promotes citrate export from the mitochondrial matrix
Which of the following is true about fatty acid synthesis.
a. these reactions occur in the mitochondria
b. no ACP intermediates are used
c. the formation of malonyl-CoA from acetyl CoA and HCO3- in an ATP dependent reaction is the first committed step
d. the formation of acetyl Co A from Malonyl-CoA by decarboxylation is the committed step
e. several anabolic reactions are reversed during fatty acid catabolism by allowing the same enzymes to catalyze the reverse reactions
c. the formation of malonyl-CoA from acetyl CoA and HCO3- in an ATP dependent reaction is the first committed step
Please list the enzymes that catalyze reactions in which NADH and FADH2 are produced in the TCA cycle.
Isocitrate DH - NADH
Alpha-ketoglutarate DHC - NADH
Succinate DH - FADH2
Malate DH - NADH
Please write out the forward reaction that results in the production of CoEnzyme A in the TCA Cycle
Succinyl CoA + GDP + Pi yields succinate + CoA + GTP
This reaction is catalyzed by succinyl CoA synthetase (named for the reverse reaction)
Please describe the deficiency, the symptoms and the underlying reason for Favism.
Deficiency: Glucose 6-P DH (G6PD)
Symptoms: Hemolytic anemia
Underlying reasons for the symptoms: Reduced G6PD activity lowers the amount of glutathione in the reduced state in RBCs. Because of this, more components of RBCs are left oxidized, which destabilizes the RBS membrane, and this RBCs are more prone to rupture
Please state how many moles of ATP are produced from one mole of glucose… when the glycerol-phosphate shuttle is being used
30
Please state how many moles of ATP are produced from one mole of glucose…
when the maleate-aspatrate shuttle is used
32
Why is there a difference in the two numbers when using the glycerol-phosphate shuttle and the malate-aspartate shuttle.
Use of the glycerol phosphate shuttle results in the production of NADH2 from NADH. Thus 2 moles of ATP are lost overall 1(1.5 ATP/Po) rather than 2(2.5 ATP/Po)
state which Complex in the ETC (I-IV) is directly affected by CO
IV
state which Complex in the ETC (I-IV) is directly affected by antimycin
III
state which Complex in the ETC (I-IV) is directly affected by H2S
IV
state which Complex in the ETC (I-IV) is directly affected by amytal
I
Please list in order all electron carriers used when the glycerol phosphate shuttle is used to bring reducing equivalents into the mitochondrion and those electrons travel through the electron transport chain.
The electrons are passed to Ubiquinone to make ubiquinol. The next carrier is complex III, then cytochrome C, then complex IV, and finally oxygen
Please identify the membrane-bound carriers in complex III and IV. List the mobile carriers and state where they are located.
Ubiquinone- the inner mitochondrial membrane, cytochrome C - the mitochondrial inter membrane space
What is true regarding Respiratory Distress Syndrome (RDS):
a. Is a result of insufficient formation of dipalmitoyl phosphatidylcholine
b. Is a result of insufficient surfactant that coats the lung surface
c. Is a result of the lungs being too difficult to expand due to increased surface tension .
d. all the above are true
d. all the above are true
Sphingolipids are an important class of membrane lipids found in all tissues, but with highest concentrations in what location?
The central nervous system
Fatty acid synthesis, and cholesterol synthesis occur in the cytosol, while beta-oxidation of fatty acids, ketone body formation and the TCA cycle all happen in the mitochondrial matrix.
a. True
b. False
a. True
Which of the following is incorrect regarding fatty acid metabolism?
a. Maximum length of fatty acids made by fatty acid synthase is 16C.
b. Desaturation of fatty acids occurs in the mitochondrion.
c. Fatty acid synthesis requires malonyl CoA as a donor molecule of acetyl groups.
d. During fatty acid synthesis, the addition of acetyl CoA is driven by CO2 release
b. Desaturation of fatty acids occurs in the mitochondrion.
Please chose the True statement:
a. In catabolism of odd-numbered fatty acids, propionyl CoA is converted to an intermediate of the TCA cycle.
b. in the catabolism of odd-numbered fatty acids, methylmalonyl CoA mutase catalyzes an intramolecular rearrangement that requires vitamin B12.
c. In the degradation of propionyl Co A, heterolytic cleavage of the coordination between cobalt and the 5´-deoxyadenosyl unit allows radical formation.
d. All the above are correct
e. Only a and b are correct
f. Only b and c are correct
e. Only a and b are correct
In the degradation of propionyl Co A, homolytic cleavage of the coordination between cobalt and the 5´-deoxyadenosyl unit allows radical formation. This is true when it is homolytic.
Please choose the correct statement:
a. Glycogen is a highly branched polymer of glucose with branch points approximately every 10 glucosyl units.
b. Straight chains of glycogen have α-1,6 linkage
c. Branch points have α-1,4 linkage.
d. Glycogenin, is a necessary initiator primer molecule, to which glucosyl residues attach
e. All the above are correct
f. Only a and d are correct
g. a, b and c are correct.
f. Only a and d are correct
Linkages are revered in b and c
Please choose the true Statement:
a. Glycogen phosphorylase catalyzes the phosphorolysis of alpha 1,6 glycosidic bonds.
b. Glycogen phosphorylase is down-regulated by phosphorylation
c. Glycogen phosphorylase is dephosphorylated in response to insulin
d. There are no true answers here.
e. Only b and d are true
c. Glycogen phosphorylase is dephosphorylated in response to insulin
