Quiz
Biochemistry MCQ
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Fragen in diesem Quiz (30)
1what is the fate of lipid digestion products absorbed by intestinal mucosal cells?
- Aexport of short chain fatty acids to the portal blood
- Bre-esteriification of long chain fatty acids forming triacylglycerols
- Cformation of lipoprotein particles: chylomicron
- Dall the above
2after an overnight fast which of the following enzymes (proteins) show low activity?
- Aglucokinase in liver
- Bhexokinase in brain
- CGluT1 transporter
- Dglucose 6 phosphatase in liver
- Eα-ketoglutaric dehydrogenase in brain
3which one of the following statements about prostaglandin synthesis is INCORRECT
- APhospholipase A2 or phospholipase C release prostaglandin precursors from plasma membrane phospholipids
- Barachidonic acid is a major precursor of prostaglandins
- CProstaglandins are derived from an essential fatty acid
- Dprostaglandins are produced through the action of lipoxygenase
- Eprostaglandins synthesis is inhibited by glucocorticoids and aspirin
4uncoupling of oxidative phosphorylation could occur with
- AA high concentration of glucocorticoids
- BA high concentration of thyroxine
- CA high concentration of adrenaline
- DA high concentration of insulin
- EA high concentration of glucagon
5sodium-glucose transporter in the intestine
- Aact as symport
- Bis located at the serosal side of the intestinal cell membrane
- Cbinds ATP
- Dtransport both sodium and glucose concentration gradient
6GLUT 2 in liver cells and pancreatic β cells
- Ahas low Km (high affinity to glucose)
- Bis suitable for glucose uptake during fasting
- Cacts as glucose sensor , along with glucokinase , in β-cells of pancreas
- Dall the above
7according to Pasteur effect
- Aglycolysis proceeds in a faster rate in presence of oxygen
- Boxygen decreases the rate of glycolysis
- Cglycolysis produces more ATP from a glucose molecule in absence of oxygen
- Doxygen decreases the production of ATP from one glucose molecule
8the bi-functional enzyme PFK2/fructose2,6-bisphosphatase
- Acontrols the level of fructose 2,6-bisphosphate ,hence the activity of PFK1
- Bis phosphorylated by cAMP-dependant protein kinase under the effect of glucagon and epinephrine
- Cis dephosphorylated by protein phosphatase under the effect of insulin
- Dall the above
9which of the following is true about fatty acid oxidation
- Athe active form of fatty acid is fatty acyl coA
- Bfatty acid is activated by acyl coA synthetase of the inner mitochondrial membrane
- Cwith fatty acid activation ATP is hydrolyzed to ADP + inorganic phosphate
- DFatty acyl coA is used only for energy production
10deficiency of carnitine acyl transferase may NOT lead to
- Afailure of fatty acid oxidation
- Bhypoglycemia
- Cketoacidosis
- Dhepatomegaly , seizures and cardiomyopathy leading to infantile death
11mitochondrial β-oxidation pathway produces propionyl CoA from
- Afatty acid with odd number of carbons
- Bphytanic acid derived from chlorophyll
- Cboth (A) & (b)
- Dneither (A) nor (B)
12Zellweger's (cerebro-hepato-renal) syndrome is characterizd by accumulation
- Aphytanic acid
- Bvery long chain polyenoic acid
- Cboth (A) & (B)
- Dneither (A) nor (B)
13ِAn enzyme is not involved in glycolysis in muscle is
- Aaldolase
- Bglyceraldehyde 3-phosphate dehydrogenase
- Cenolase
- Dpyruvate kinase
- Ebisphosphoglycerate mutase
14the best description of the difference between glucokinase and hexokinase is
- Ahexokinase is found in liver and kidney , while hexokinase is present in nearly all tissues
- Bhexokinase has much higher Km for glucose
- Cglucokinase is found only in tissues that are totally dependent on glucose for fuel , such as brain & RBCs
- Dglucokinase & hexokinase are zymogens
- Eglucokinase but not hexokinase is induced by insulin
15An abnormal accumulation of galactose 1-p in liver is usually caused by a deficiency
- Aglucose 6-phosphate dehydrogenase
- Bglucose 6-phosphatse
- Cgalactokinase
- Dgalactose 1-phosphate uridylyl transferase
- Ehexokinase
16the oxidative decarboxylation of all α-keto acids is similar to that of pyruvate. A common requirment for all is
- ANADP
- BAcetyl CoA
- CLipoic acid
- Dα -ketoglutarate
- EGDP
17mitochondria in brown fat of human infants increase heat generation .this result from an increased rate of electron transport due to
- Ainhibition of ADP-ATP antiporter
- Binhibition of F1-Fo ATP synthase
- Cblockage of NADH reoxidation
- Dincreased permeability of the inner mitochondrial membrane
- Edecreased rate of oxygen consumption
18all the electron carrying groups of the respiratory chain
- Aare fixed to the inner mitochondrial membrane
- Bare arranged in an order of descending redox potential
- Ccontain iron as an electron acceptor
- Dparticipate in the building up of the proton gradient
- Enone of the above
19the following enzyme is a constituent of pentose phosphate pathway
- Aglucose 6-phosphatase
- Bphosphorylase
- Chexokinase
- Dglucose 6-phosphate dehydrogenase
- Ephosphohexoisomerase
20a substance that is not an intermediate in formation of glucuronic acid from glucose
- AUDP-galactose
- BUDP-glucose
- CGlucose 6-phosphate
- DUDP-glucuronic acid
- Eglucose 1-phosphate
21in the break down of muscle glycogen the predominant product is
- Aglucose
- Bglucose 1-phosphate
- CUDP-glucose
- Dmaltose
- Emaltriose
22the regulation of glycogenolysis in muscle differ from that in the liver
- Amuscles lack receptors of glucagon
- Bonly the liver uses β-adrenergic receptors for this regulation
- Conly muscles respond to epinephrine
- Dmuscle glycogenolysis does not respond to stimulation by intracellular calcium
- Emuscle produces mostly glucose from glycogen
23mammalian fatty acids desaturase systems introduce double bonds
- Aat Δ4, Δ5, Δ6, Δ9 positions
- Bat ω3, ω6 and ω9 positions
- Cbetween an existing double bond and methyl carbon
- Dall the above
24lypolysis in adipose tissue is initiated by
- AFood intake
- Bketoacidosis
- Cfasting
- Dhigh insulin/glucagon ratio
- Ehigh fatty acid concentration
25The enzyme required for both the synthesis of acetoacetate and its utilization as a fuel is
- Asuccinyl coA : acetoacetate CoA transferase
- BHMG-CoA synthase
- Cthiolase
- DHMG-CoA lyase
- Eβ-hydroxybutyrate dehydrogenase
26Receptor-mediated uptake of excess LDL results in all the following Except
- Aincreased estrification of cholesterol
- Bincreased production of mevalonate
- Cdecreased synthesis of HMG-CoA reductase
- Ddecreased synthesis of the LDL recepttor
- Edecreased receptor-mediated endocytosis of LDL
27In man serum lipoprotein fraction with the highest cholesterol content is
- Aα-lipoprotein
- Bβ-lipoprotein
- Cpre β-lipoprotein
- Dchylomicrons
- Epre-albumin
28secondary bile acids are distinguishable from the primary bile acids because they lack
- Aglycine
- Btaurine
- Ca hydroxyl group
- Da methyl group
- Ea carboxylate group
29what is the enzyme used for cholesterol storage
- AHMG-CoA reductase
- BLecithin cholesterol acyl transferase
- Clipoprotein lipase
- DAcyl CoA cholesterol acyl transferase
- Echolesterol esterase
30cori cycle transfers
- Aalanine from muscle to liver
- Blactic from liver to muscle
- Clactic from exercising muscle or RBCs to liver
- DGlucose from muscle to liver
Informationen
- Beschreibung
- Quiz am Biochemistry MCQ, erstellt von #أطباء_2020 am 12/01/2015.
- Autor
- #أطباء_2020
- Sprache
- English
- Aufrufe
- 477
- Schlagwörter
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