Exam 2 Review Flashcards
P450 cytochromes are members of which family of oxidoreductase?
A: Catalase
B: Hydroperoxidase C: Oxidase
D: Oxygenase
D
Which of the following statements about the enzymes used in fructose metabolism is 1/1 incorrect (or False)?
A: Fructokinase phosphorylates Fructose from diet into Fructose 1-phosphate.
B: Aldolase A hydrolyzes Fructose 1-phosphate into Dihydroxyacetone phosphate and D-glyceraldehyde.
C: Thiokinase phosphorylates D-Glyceraldehyde into Glyceraldehyde 3-phosphate.
D: Aldolase B is the predominant form of the enzyme in the liver.
B
Which of the following statements about enzymes in glycolysis and gluconeogenesis is 1/1 incorrect (or False)?
A: Glycerol-3-phosphate dehydrogenase reduced glycerol 3-phosphate into Dihydroxyacetone phosphate.
B: Phosphoenolcarboxykinase converts pyruvate into oxaloacetate
C: Malate dehydrogenase converts malate into oxaloacetate.
D: Fructose 1,6-bisphosphatase converts Fructose 1,6-bisphosphate into Fructose 6 phosphate.
A
A patient visits his general practioner (GP) complaining of abdominal cramps and diarrhea after drinking milk. What is the most likely cause of the patient’s problem?
A: Lack of intestinal sucrase-isomaltase
B: Lack of intestinal lactase
C: Lack of pancreatic amylase
D: Lack of cellulase
B
If a person decides to go on a crash diet and has only water for several days, which of the following molecules will exist in a higher concentration in the person’s blood? A: Ketone bodies B: Insulin C: Glucose D: Triglycerides
A
Statins have proved very effective against hypercholesterolemia, by which of these processes?
A: Inhibition of the conversion of HMGCoA to mevalonate
B: Inhibition of the conversion of Mevalonate to HMGCoA
C: Inhibition of the formation of Farnesyldiphosphate
D: Preventing absorption of cholesterol from tissues.
A
Phosphatidylinositol is hydrolyzed to Diacylglycerol (DAG) and Inositol triphosphate (IP3), using which of the following enzymes? A: Phospholipase B B: Phospholipase C C: Phospholipase D D: Phospholipase A2
B
The subcellular site of the breakdown of long chain fatty acids to acetylCoA via beta oxidation is which of the following?
A: The cytosol
B: the matrix in the mitochondria.
C: The endoplasmic reticulum.
D: The intermembrane space of the mitochondria.
B
Which of the following statements about gangliosides is incorrect (or False)?
A: They are derived from galactosylceramide.
B: They contain one or more molecules of sialic acid.
C: They are present in nervous tissue in high concentrations.
D: The ganglioside, GM1 is the receptor for cholera toxin in the human intestine.
A
Which of the following statements is incorrect (or False)?
A: Ca+2 activates Phosphorylase kinase b to Phosphorylase kinase a, by phosphorylation.
B: Ca+2 activates Phosphorylase kinase b to Phosphorylase kinase a, by dephosphorylation.
C: Ca+2 activates Glycogen synthase ‘b’ to glycogen synthase ‘a’ by dephosphorylation.
D: Phosphodiesterase deactives cAMP by hydrolysis.
B
Which of the following statements is incorrect (or False)?
A: Pyruvate carboxylase catalyzes the carboxylation of pyruvate to oxaloacetate.
B: Phosphoenolpyruvate carboxykinase catalyzes the decarboxylation and phosphorylation of oxaloacetateto Phosphoenolpyruvate.
C: Pyruvate Dehydrogenase converts Lactate into Pyruvate.
D: Action of Adenylyl cyclase of ATP, followed by phosphodiesterase converts ATP into 5’ AMP.
C
Which of these statements is incorrect (or False)?
A: Cholesterol is synthesized in the body entirely from AcetylCoA, and cholesterol synthesis in the liver is regulated partly by cholesterol in the diet.
B: Glycolipids are important constituents of nervous tissue such as brain and the outer leaflet of cell membranes.
C: Fluidity of a fatty acid increases with chain length and decreases with increase in the degree of unsaturation.
D: Eicosanoids make up an important group of physiologically and pharmacologically active compounds such as prostaglandins, thromboxanes, leukotrienes and lipoxins.
C
Which of the following statements is incorrect (or False?)
A: Fatty acid synthase has 6 enzyme activities.
B: The main source of NADPH for lipogenesis is the Oxidative process of Pentose Phosphate Pathway.
C: 3 moles of NADPH is used in one cycle of biosynthesis of fatty acid.
D: Elongation of Fatty acid chain occurs in the Endoplasmic reticulum.
C
Which of the following statements is incorrect (or False)?
A: Lipogenesis occurs in the mitochondria.
B: Production of MalonylCoA is the first step in fatty acid synthesis.
C: Biotin is the vitamin required for carboxylation of AcetylCoA.
D: AcetylCoA Carboxylase will carboxylate AcetylCoA to MalonylCoA.
A
Which of the following statements is incorrect (or False)?
A: Linoleic and alpha Lenolenic acids are the only fatty acids known to be essential fatty acid.
B: Arachidonic acid can be derived from linoleic acid, in most mammals.
C: The first double bond introduced into a saturated fatty acid is nearly always in the delta-9 (9th position).
D: Plants cannot synthesize nutritionally essential fatty acids by introducing double bonds at delta-9 (9th carbon) or delta-12 (12th carbon) or delta-15 (15th carbon)
D
Which of the following statements is incorrect (or False)?
A: Geranyl diphosphate gives rise to Dolichol and Ubiquinone.
B: Mevalonate is the reduced product of HMG CoA.
C: Statins inhibit the action of HMG CoA reductase.
D: Mevalonate is converted to Mevalonate 3-phospho-5-diphosphate and then decarboxylated to Isopentyldisphosphate.
A
Which of the following statements is incorrect (or False)?
A: Oxidation of Fatty acids occurs in the mitochondria.
B: Long chain fatty acids penetrate the inner mitochondrial membrane as Carnitine derivatives.
C: One cycle of beta oxidation of fatty acid produces one NADH and one FADH2 molecule.
D: Oxidation of Fatty acids with an odd number of carbon atoms yields AcetylCoA and a SuccinylCoA molecule.
D
Which of the following statements is incorrect (or False)?
A: Carnitine is beta hydroxy-gamma trimethylammonium butyrate.
B: Ketogenesis is regulated at two steps.
C: If Stearic acid is metabolized, 9 AcetylCoA’s are formed along with 8 NADH and 8 FADH2 molecules.
D: Peroxisomes can oxidize the fatty acid - docasahexenoic acid (DHA or Cervonic acid).
B
Which of the following statements is incorrect (or False)?
A: Free fatty acid is converted to AcylCoA by the enzyme Acyl-CoA synthetase.
B: HMG-CoA synthetase synthesizes HMG from acetoacetylCoA and AcetyCoA.
C: HMG-CoA lyase hydrolyzes HMGCoA into acetoacetate and AcetylCoA.
D: 3-hydroxybutyrate dehydrogenase will oxidize the C=O (carbonyl or oxo) group of acetoacetate
D
Which of the following statements is incorrect (or False)?
A: 2 moles of AcetylCoA is required to produce Acetoacetate.
B: Decarboxylation of Acetoacetate produces Acetone.
C: Reduction of acetoacetate produces alpha hydroxybutyrate (or alpha hydroxybutanoate).
D: Ketone bodies serve as fuel for extrahepatic tissues.
C
Which of the following statements is incorrect (or False)? 0/1
A: Long chain omega-3 fatty acids promote the synthesis of less inflammatory prostaglandins and leukotrienes.
B: Phophatidylcholine plays a role in programmed cell death (apoptosis).
C: Peroxidation of lipids containing saturated fatty acids lead to a generation of free radicals that damage tissue and cause disease.
D: Lecithin is a condensation product of phosphatidic acid and Choline.
C
Which of the following statements is incorrect (or False)? 1/1
A: Triglycerides contain a glycerol and three fatty acids, where the 2nd fatty acid is unsaturated.
B: Phosphatidic acid contains a glycerol molecule to which two fatty acids are condensed on the 1st and 2nd carbon and the 3rd carbon has a phosphate ester group.
C: When phosphatidic acid is condensed with Choline, it is referred to as Lecithin.
D: When phosphatidic acid is condensed with Ethanolamine, it is referred to as Lecithin
D
Which of the following statements is incorrect (or False)?
A: Oleic acid contains 18 C’s, 1 double bond and it is a C-9 from the COOH group.
B: Linoleic acid contains 18 C’s, 2 DBs and the DBs start at C-9 and C-12 from the COOH group.
C: Linolenic acid contains 18 C’s, 3 DBs and the DBs start at C-9, C-12 and C-15 from the COOH group.
D: Arachidic acid contains 20 C’s, 4 DBs, starting at C-5, C-8, C-11 and C-14 from the COOH group.
D
Which of the following statements is incorrect (or False)?
A: Phosphatidic acid contains a glycerol molecule to which two fatty acids are condensed on the 1st and 2nd carbon and the 3rd carbon has a phosphate ester group.
B: Arachidonic acid contains 20 C’s, 4 DBs, starting at C-5, C-8, C-11 and C-14 from the COOH group.
C: Bile acids are derived from cholesterol or oxidation products of cholesterol.
D: Glycolipids contain a sphingosine molecule to which is attached a fatty acids at the amine group and a phosphate and a choline molecule at the primary alcohol.
D