Biochem MCQs PDF

Which of following is correct about enzyme? A. all enzymes are proteins B. enzymes can not be updated in living tissue C. enzymes are biocatalysts that catalyze the multiple dynamic processes in the body D. the substrates of...

Which of following is correct about enzyme? A. all enzymes are proteins B. enzymes can not be updated in living tissue C. enzymes are biocatalysts that catalyze the multiple dynamic processes in the body D. the substrates of enzyme are all organic compounds E. catalytic DNA and RNA are not biocatalysts Answer: C Liaoning Medical University [email protected] Specificity of enzyme refers to： A. enzymes have highly specificity for coenzymes B. the ability of an enzyme to discriminate between two competing substrates C. specific site that enzyme exist D. different catalytic mechanism E. different classification of enzymes Answer: B Liaoning Medical University [email protected]  Isoenzymes are enzymes that： A. catalyze the same reaction B. have the same structure C. have the same physiocochemical properties D. have the same immunological properties E. show the same electrophoretic mobility Answer: A Liaoning Medical University [email protected]  Which of following is not correct about LDH isoenzymes? A. LDH has five different isoenzymes B. contains H and M subunits C. different isoenzymes shows a characteristic electrophoretic mobility D. have the same Km to the same substrate E. two subunits are products of different genes Answer: D Liaoning Medical University [email protected]  Denatured apoenzyme lost its activity because A. apoenzyme is decomposed to amino acids B. primary structure of apoenzyme is destroyed C. spatial structure of apoenzyme is destroyed D. apoenzyme does not dissovle in water E. it loses activator Answer: C Liaoning Medical University [email protected]  Which of following is not the function of coenzyme？ A.group transfer B.hydrogen transfer C.electron transfer D.carrier of metabolite E.determining the specificity of enzyme Answer: E Liaoning Medical University [email protected]  Which of following is not the characteristics of enzymatic reactions? A.high efficiency B.stereospecificity C.absolute specificity D.can be regulated E.proximity and orientation Answer: E Liaoning Medical University [email protected] Liaoning Medical University [email protected]  Which of following is not correct about active site of an enzyme? A. it is formed by groups that primary structure is close to each other in the polypeptide sequence. B. there are binding groups and catalytic groups in it. C. it binds substrate and catalyzes the reaction. D. all groups in active site are termed the essential groups. E. Substrate bind to the active site at a region complementary to substrate that will undergo chemical change. Answer: A Liaoning Medical University [email protected]  Which of following is correct about active site of enzyme？ A. all essential groups must located in active site B. all enzymes must have active site C. all active site binds and orients cofactors D. all active site binds and orients metal ions E. all inhibitors act on active site Answer: B Liaoning Medical University [email protected]  Which of following determines specificity of enzymatic reaction? A.coenzyme B.apoenzyme C.metal ion D.prosthetic group E.holoenzyme Answer:B Liaoning Medical University [email protected]  Which of following is not correct about Km? A. Km is one of the characteristic constants of the enzyme B. Km is independent of enzyme structure C. Km is independent of enzyme concentration D. Km is equivalent to the substrate concentration at which V is equal to Vmax/2 E. Km reflects approximately the affinity of enzyme to substrate Answer: B Liaoning Medical University [email protected]  When the velocity of enzyme catalyzed reaction achieves 80% of Vmax, the substrate concentration is equal to: A: 1 Km B: 2 Km C: 3 Km D: 4 Km E: 5 Km Answer: D Liaoning Medical University [email protected]  The kinetic property of competitive inhibition is： A.Vmax is unchanged，Km is increased B.Vmax is unchanged，Km is decreased C.Vmax is decreased，Km is unchanged D.Vmax is decreased，Km is increased E.Vmax is decreased，Km is decreased Answer: A Liaoning Medical University [email protected]  The relationship between competitive inhibitor and substrate is that they have: A. same physico-chemical property B. same function C. same molecular weight D. same solubility E. similar structure Answer: E Liaoning Medical University [email protected]  The effect of temperature on the rate of enzymatic reactions is: A. the higher the temperature, the higher the reaction rate B.the lower the temperature, the higher the reaction rate C. each enzyme has an optimum temperature at which it operates at maximal efficiency D. optimum temperature is one of the characteristic constants of the enzyme E. an optimum temperature of enzymes is usually 37。C Answer: C Liaoning Medical University [email protected]  Which of following is independent of Km? A.enzyme structure B.enzyme concentration C.temperature D.substrate E.pH Answer: B Liaoning Medical University [email protected] The kinetics of enzymatic reaction is the study on： A.spatial conformation of enzyme B.electrophoretic mobility of enzyme C.the active site of enzyme D.gene origin of enzyme E.the velocity of enzymatic reactions and influence of various elements on it Answer: E Liaoning Medical University [email protected]  Which of followings is not the factors to affect The velocity of enzyme-catalyzed reaction? A. substrate concentration B. enzyme concentration C. zymogen concentration D. pH E. temperature Answer: C Liaoning Medical University [email protected]  Which of following is not correct about competitive inhibitor? A.its structure resembles that of the substrate B.it competes with the substrate for the active site of an enzyme C.it combines reversibly with the enzyme D.it combines with the enzyme to form an EI complex without leading to catalysis E.it combines with the enzyme covalently Answer: E Liaoning Medical University [email protected] Liaoning Medical University [email protected]  Which of following is not correct about allosteric enzyme? A. it contains many subunits B. allosteric effector binds with enzyme noncovalently C. allosteric effector binds with enzyme reversibly D. allosteric effector binds to active site of enzyme E. it is known as rate-limiting enzyme Answer: B Liaoning Medical University [email protected]  Which of following is not correct about covalent modification? A. enzyme binds with specific chemical groups covalently B. it is a fast regulation C. it consumes ATP D. the most common type is phosphorylation E. activity of enzyme increased after phosphorylated Answer: E Liaoning Medical University [email protected]  Which of followings are correct about zymogen? A.it is inactive B. can be converted into active enzyme by the cleavage of some covalent bonds in their peptide chains C.it is activated by some metal ions D.it has no acti vi ty for d eficiency o f essential groups E. the essence of zymogen activation is the creation or exposure of the active site of an enzyme Answer: ABE Liaoning Medical University [email protected]  The fast regulation of enzymatic reaction includes： A.phosphorylation B.allosteric regulation C.acetylation D.methylation E.the synthesis of enzyme can be repressed Answer: ABCD Liaoning Medical University [email protected]  Terms: 1．competitive inhibition 2．covalent modification 3．Isoenzymes 4．allosteric regulation Question: 1．What is activation of zymogen？List the significance of it. 2 ． W ha t a r e t h e c h a r a c t e r i s t i c s o f competitive inhibition? Liaoning Medical University [email protected]  Terms: 1．enzyme 2．the active site of enzyme 3．essential group 4．competitive inhibition 5．Km 6．covalent modification 7．activation of zymogen 8．Isoenzymes 9．allosteric regulation Liaoning Medical University [email protected]  Which of the following metabolic process is completed in mitochondrion totally A. aerobic oxidation B. petose phosphate pathway C. gluconeogenesis D. oxidative phosphorylation E. glycogenesis Answer: D Liaoning Medical University [email protected]  Which of the following is the most important element in the regulation of oxidative phosphorylation? A.FADH2 B.O2 C.Cytaa3 D.[ADP]/[ATP] E. NADH Answer: D Liaoning Medical University [email protected]  Which of the following is not the energy-rich compound? A. creatine phosphate B. ATP C. phosphoenolpyruvate(PEP) D. 1,3-bisphoglycerate E. 2,3-bisphoglycerate Answer: E Liaoning Medical University [email protected]  Which of following is the carrier of NADH from cytosol to mitchondria? A. carnitine B. malate C. oxaloacetate D. α-ketoglutarate E. aspartate Answer: B Liaoning Medical University [email protected]  How many ATPs will be produced when 1 cytosolic NADH is transported into the mitochondria by α-glycerophosphate shuttle? A.1 B.2 C.3 D.4 E.5 Answer: B Liaoning Medical University [email protected]  The characteristic of biological oxidation is: A. direct combination of hydrogen and oxygen to form water B. nonenzymatic reaction C. taken place mainly in cytosol D. energy released gradually and high availability E. not regulated by circumstance Answer: D Liaoning Medical University [email protected]  The pathway that NADH produced in the cytoplasm during glycolysis go into the mitochondria is: A. citrate-pyruvate cycle B. the Cori cycle C. GSH cycle D. α-glycerophosphate shuttle E. alanine-glucose cycle Answer: D Liaoning Medical University [email protected]  NADH equivalents are transported from the cytosol to the mitochondrial matrix with which shuttle systems? A.α-glycerolphosphate shuttle B. malate-aspartate shuttle C.citrate-pyruvate cycle D.alanine-glucose cycle E.citrate acid cycle Answer: AB Liaoning Medical University [email protected]  Terms: 1．Biological oxidation 2．Respiratory chain 3．Oxidative phosphorylation 4．Substrate level phosphorylation 5．P/O ratios Question: List the order of two important respiratory chains Liaoning Medical University [email protected]  generation of ATP in aerobic oxidation of glucose Reactions Methods of Moles of ATP pathway Catalyzed by ATP production formed per mol of glucose Glycolytic Glyceraldehyde 3-phosphate dehydrogenase Respiratory chain Oxidation of 2 NADH 6 or 4 pathway Phosphoglycerate kinase Phosphorylation at substrate level 2 Pyruvate kinase Phosphorylation at substrate level 2 Allow for consumption of ATP by reactions catalyzed by hexokinase and phosphofructokinase -2 Production of Pyruvate dehydrogenase Respiratory chain Oxidation acetyl CoA complex 6 of 2 NADH Tricarboxylic Isocitrate dehydrogenase Respiratory chain Oxidation of 2 NADH 6 acid cycle Alpha-ketoglutarate Respiratory chain Oxidation of 2 NADH 6 Dehydrogenase complex Succinyl CoA synthetase Phosphorylation at substrate level 2 Succinate dehydrogenase Respiratory chain Oxidation of 2 FADH2 4 Malate dehydrogenase Respiratory chain Oxidation of 2 NADH 6 Total per mole of glucose under aerobic conditions: 36 or 38 ATPs  Summary of citric acid cycle 1. Location: mitochondria 2. Original material: Oxaloacetate, Acetyl-CoA, GDP, 3NAD+, FAD 3. End product: Oxaloacetate, GTP, 3 NADH+H+, FADH2 , 2CO2 4. Key enzymes: citrate synthase isocitrate dehydrogenase - ketoglutarate dehydrogenase complex 5. Overall process of TCA cycle: Acetyl CoA+3NAD++FAD+GDP+Pi+2H2O CoA-SH+3(NADH+H+)+FADH2+2CO2+GTP 6. Net amounts of ATP produced only in TCA cycle: 12 Liaoning Medical University [email protected]  How many mols of ATP are yielded when 1 mol lactate is oxidized to CO2 and H2O? List the main steps and key enzymes. Liaoning Medical University [email protected]  NADH+H + LDH lactate pyruvate cytosol NAD+ NADH+H+ pyruvate Acetyl CoA Pyruvate dehydrogenase NAD + complex oxaloacetate citrate synthase malate NADH+H+ citrate f umarate FADH2 isocitrate isocitrate NAD+ succinate dehydrogenase GTP NADH+H+ NADH+H+ succinyl CoA α -ketoglutatrate α -ketoglutatrate dehydrogenase complex Mitochondrion Liaoning Medical University [email protected]  Key enzyme: LDH, Pyruvate dehydrogenase complex, citrate synthase, isocitrate dehydrogenase, α-ketoglutarate dehydrogenase complex, malate dehydrogenase. Amount of ATP: Cytosol: 1 NADH 2/3 ATP Mitochondrion: 4 NADH 4×3=12 ATP 1 FADH2 2 ATP GTP Total:2/3+12+2+1=17/18 Liaoning Medical University [email protected]  Physiological Significance of Aerobic Oxidation In one word， “provide energy” Liaoning Medical University [email protected]  How many ATPs are produced by the oxidation of a molecule of aceyl CoA via the citric acid cycle? A.9 B.10 C.11 D.12 E.13 Answer: D Liaoning Medical University [email protected]  The products of the TAC are: A.1 pairs of FADH2 B.3 pairs of NADH+H+ C.1 molecule of GTP D.2 molecules of CO2 E.2 molecules of GTP Answer: ABCD Liaoning Medical University [email protected]  The key enzymes of Krebs Cycle: A.citrate synthase B.isocitrate dehydrogenase C.α-ketoglutarate dehydrogenase complex D.fumarase E.malate dehydrogenase Answer: ABC Liaoning Medical University [email protected]  Which of following is correct about aerobic oxidation? A. glucose is completely oxidized to CO 2 ,H 2 O and energy under aerobic conditions B. takes place in the mitochondria C. this process is the major process to provide energy for most tissues D. 1 mol of glucose was oxidized completely will be generated 36 or 38 mol of ATP E. it start from Oxidation of pyruvate to acetyl- CoA in mitochondrion Answer: ACD Liaoning Medical University [email protected]  Which of the following enzyme uses FAD as prothetic group? A.lactate dehydrogenase B.isocitrate dehydrogenase C.succinate dehydrogenase D.α-ketoglutarate dehydrogenase complex E.malate dehydrogenase Answer: C Liaoning Medical University [email protected]  n Significance of glycolysis* ü To provide ATP in the absence of oxygen, such as run 100- meters dash. ü Glycolysis is the main way to produce ATP in some tissues, even though the oxygen supply is sufficient, such as red blood cells (Lack mitochondria), retina, testis, skin, medulla of kidney. ü In clinical practice, such as heart failure, circulation failure, respiration failure, excessive loss of blood. Liaoning Medical University [email protected]  The end-product of glycolysis is: A. pyruvate B. lactate C. acetyl-CoA D. oxaloacetate E. uric acid Answer: B Liaoning Medical University [email protected]  The key enzyme of the glycolysis is: A. pyruvate carboxylase B. pyruvate dehydrogenase C. pyruvate kinase D. fructose 1,6-bisphophatase E. LDH Answer: C Liaoning Medical University [email protected]  In glycolysis, substrate level phosphorylation is catalyzed by: A. hexokinase B. glyceraldehyde 3-phosphate dehydrogenase C. phosphofructokinase-1 D. phosphoglycerate kinase E. pyruvate dehydrogenase Answer: D Liaoning Medical University [email protected]  Why erythrocytes metabolize glucose by anaerobic glycolysis? A. absence of oxygen B. absence of TPP C. absence of coenzyme A D. lack of mitochondria E. lack of microsome Answer: D Liaoning Medical University [email protected]  Which of following about glycolysis is correct? A. the end product is pyruvate B. occurs in the cytosol of all cells C. generates ATP via oxidative phosphorylation D. does not consume ATP E. all the reaction are reversible Answer: B Liaoning Medical University [email protected]  Which of following will emerge in the urine after a healthy person takes heavy exercises? A.pyruvate B.lactate C.glucose D.oxaloacetate E.acetoacetate Answer: B Liaoning Medical University [email protected]  Aerobic Oxidation of Glucose The process of complete oxidation of glucose to CO2 and H2O with liberation of energy as the form of ATP is named aerobic oxidation. This process is the major process to provide energy for most tissues. Liaoning Medical University [email protected]  What are the most important products the cells generate by means of the pentose phosphate pathway? A. lactate and ATP B.ribose-5-phosphate and NADPH C.NADP+ and ribose-5-phosphate D.NADPH and UDP-ribose E.ribulose-1,5-biophosphate and NADPH Answer: B Liaoning Medical University [email protected]  NADP+ is the coenzyme of: A. LDH B. succinate dehydrogenase C. malate dehydrogenase D. glyceraldehydes-3-phosphate dehydrogenase E. glucose -6 phosphate dehydrogenase Answer: E Liaoning Medical University [email protected]  Which of following is basic process of aerobic oxidation of glucose? A. glycolytic pathway B. oxidation of pyruvate to acetyl-CoA C.TAC D. oxidative phosphorylation E. glycolysis Answer: ABCD Liaoning Medical University [email protected] Liaoning Medical University [email protected]  Clinic Aspect Glycogen Storage Diseases n Glycogen storage diseases are caused by inherited defects of one or more enzymes involved in glycogen synthesis or degradation Liaoning Medical University [email protected]  Glycogen Storage Diseases n In afflicted individuals, the concentration of glucose in the blood is low, and glycogen accumulates in the liver and kidneys because glucose is not secreted normally. Accumulation of glucose 6-phosphate inhibits glycogen phosphorylase and activates glycogen synthase. Relief can be obtained by eating many small meals containing carbohydrate that is slowly hydrolyzed. Ingestion of excess carbohydrate, which is stored in the liver, may result in a greatly enlarged liver. Liaoning Medical University [email protected]  The direct donor of glucose in glycogenesis is: A.ADP-glucose B.CDP-glucose C.UDP-glucose D.glucose-1-phosphate E.glucose-6-phosphate Answer: C Liaoning Medical University [email protected]  Glycogen stored in the muscle can not maintain blood glucose levels because the tissue does not contain : A. pyruvate kinase B. glucose 6-phosphatase C. glycogen phosphorylase D. debranching enzyme E. pyruvate carboxylase Answer: B Liaoning Medical University [email protected]  After phosphorylation of glycogen synthase and phosphrylase: A. activity of glycogen synthase and phosphorylase unchanged B. glycogen synthase is active, phosphorylase is inactive C. both glycogen synthase and phosphorylase are inactive D. both glycogen synthase and phosphrylase are active E. glycogen synthase is inactive, phosphrylase is active Answer: E Liaoning Medical University [email protected]  The major regulation of glycogenolysis and glycogenesis is: A. feedback regulation B. positive coordinate regulation C. negative coordinate regulation D. methylation/demethylation E. phosphorylation/dephosphorylation Answer: E Liaoning Medical University [email protected] Liaoning Medical University [email protected]  Study Questions Choose the ONE correct answer The synthesis of glucose from pyruvate by gluconeogenesis: A. occurs exclusively in the cytosol. B. is inhibited by an elevated level of glucagon. C. requires the participation of biotin. D. involves lactate as an intermediate. E. requires the oxidation/reduction of FAD. Answer: C Liaoning Medical University [email protected]  Gluconeogenesis is the synthesis of: A. glucose from non-carbohydrate precursors B. glycogen from glucose C. pyruvate from glucose D. fatty acids from glucose E. amino acids from glucose Answer: A Liaoning Medical University [email protected]  Which of the following statements is correct about lactate? A.it is the dead end product of anaerobic respiration in the muscle and liver B.it is transported from the muscle to the liver where it enters glycolysis C.it is transported from the liver to the muscle where it enters the citric acid cycle D.it is transported from the muscle to the liver where it is converted to glucose via gluconeogenesis E.it is transported from the liver to the muscle where it reforms glucose Answer: D Liaoning Medical University [email protected]  The major substrates for gluconeogenesis are: A.lactate B.glycerol C.Ala D.Leu E.Thr Answer: ABCE Liaoning Medical University [email protected]  Which of following is not correct about gluconeogenesis? A.is the process of converting non-carbohydrates to glucose or glycogen B. is a reverse process of glycolysis C. noncarbohydrate includes fatty acids and amino acids and intermediate products mainly D. key enzymes of gluconeogenesis exit in cytosol E. glycolysis and gluconeogenesis were regulated reciprocally Answer: BCD Liaoning Medical University [email protected]  Which of the following reaction is completed in mitochondrion? A. glycolysis B. gluconeogenesis C. glycogen synthesis D. Citric acid cycle E. pentose phosphate pathway Answer: D Liaoning Medical University [email protected]  Which of following is the major organ to regulate the concentration of glucose? A. brain B. liver C. kidney D. adrenal gland E. pancreas Answer: B Liaoning Medical University [email protected]  Explain the following terms: 1. Glycolysis (location, initial material, the end product, reaction condition) 2. Aerobic oxidation 3. Pentose phosphate pathway 4. Glycogenesis and Glycogenolysis 5. Gluconeogenesis 6. Substrate cycle 7. Substrate level phosphorylation 8. Cori cycle Liaoning Medical University [email protected]  Answer the following questions 1. What is the significance of glycolysis? 2. Indicate the key enzymes of glycolysis. 3. Indicate the physiological importance of tricarboxylic acid cycle. 4. What is the physiological importance of pentose phosphate pathway? 5. Indicate the key enzymes of glycogenesis and glycogenolysis. 6. Indicate the key enzymes of gluconeogenesis. 7. What is the physiological importance of gluconeogenesis? 8. Explain how the glycogenesis and glycogenolysis are regulated. 9. How many mols of ATP are yielded when 1 mol lactate is oxidized to CO2 and H2O? List the main steps and key enzymes. Liaoning Medical University [email protected] Lipids are metabolized in different ways in vivo The metabolism of lipids includes two main aspects: Anabolism (biosynthesis) of lipids is the process in which lipids are synthesized from smaller, simple precursors. Catabolism of lipids is the degradative phase of metabolism in which lipids are converted into smaller, simpler end products.  Practise 1 lipids are classified into ( )( )( ) Simple lipids Complex lipids Precursors and derivatives of lipids 2 glycerophospholipids are composed of ( )( )( )( ) fatty acid, Glycerol phosphoric acid nitrogen-containing bases 3 Depending on the nature of hydrocarbon chain fatty acid are classified into ( )( ) Saturated, Unsaturated 4. ( )( )( ) are called essential fatty acids, Linoleic acid , linolenic acid , arachidonic acids 5 During the digestion of Lipid the ( )take part in the emulsification process bile salts 6. pancreatic lipase requires a further pancreatic protein ----( ) for its activity colipase 7. During catalysis process of lipid, need some pancreatic lipase, they are mainly ( )( )( )( ) steapsin; colipase ; phospholipase A2(PLA2) , cholesteryl esterase 8、 Digestion of lipids contain two main process , they are ( )( ) Emulsification, catalysis  Defination 1 EFA 2 Colipase 3 unsaturated fatty acid Short answer question 1 explain the classification of fatty acid 2 what is the function of bile salts during the digestion of lipids 2 what is the function of colipase during the digestion of lipids  Sth for the Mid-term exam 1\ Choice (20 question , 2point per question ,40points all ) 2\ Explain the word (5 questions, 3 point per question,15 points all ) 4\Short question(3 questions , 10point per question,30points all ) 5\ Long question (1 question , 15 point per question,15points all ) No review for all the students together Review by yourself , if you have any question can go to the office ask the teacher who give you class Office site : the first building , 5 floor , 514 room  Why mammals can not synthesize essential fatty acid (EFA)? Because they lack the enzymes to introduce double bonds at carbon atoms beyond C-9 in the fatty acid chain.  Summary Places: small intestine(use food fat to synthesize TG) liver (main organ for synthesize, can not store) adipose tissue (synthesize and store, don’t have glycerol kinase so can not use glycerol) Materials: Glycerol glycerol 3-phosphate free fatty acid monoacylglycerol  Practice uThe enzyme responsible for fatty acid synthesis are located in the( )of the cell cytoplasm uThe activated intermediates of fatty acids synthesis are bound to the ( ) acyl carrier protein , ACP uFatty acid synthesis is carried out by a multienzyme complex known as( ) fatty acid synthase u( )is the reducing agent for fatty acid synthesis NADPH  Main Site! ( ) is the main tissue for FA synthesis 16C palmitate is synthesis in ( ) elongation of fatty acid chain take place in ( ) and ( ) Liver cytosol： Mitochondria endoplasmic reticulum p Acetyl CoA for FA synthesis mainly come from the metabolism of ( ). Transport system to export acetyl CoA from matrix to cytosol for FA syntheis is ( ) glucose , citrate-pyruvate cycle  The sources of NADPH For FA syntheis mainly come from ( ) Pentose Phosphate pathway lThe carboxylation of Acetyl CoA is catylazed by ( ), The production of the reaction is ( ). the prosthetic group of the enzyme is ( ). It serve as the carrier of ( ) Acetyl-CoA Carboxylase Malonyl-CoA biotin CO2 The sequence of reactions, namely ( )( )( ) ( ) are repeated during the synthesis of FA condensation, reduction, dehydration and reduction The site for the Biosynthesis of Triacylglycerols are ( )( )( ),( )is the main organ Liver , adipose tissue, intestines Liver The are two pathway fro the synthesis of TG , they are ( ), ( ) Monoacylglycerol pathway Diacylglycerol pathway The utilization of glycerol depends on whether the tissues possess( ) glycerol kinase.  Defination Lipogenesis Citrate-pyruvate cycle  Short answer question 1 Please write out the Materials for fatty acid synthesis 2, The sources of NADPH for FA synthesis 3, Please explain Why mammals can not synthesize essential fatty acid (EFA)? 4, When you eat more glucose , you will become fat, please explain this phenomenon  Summay uThe ketone bodies----acetone, acetoacetate, and β- hydroxybutyrate---are formed in liver mitochondria uacetoacetate, and β-hydroxybutyrate serve as fuel in extrahepatic tissues, through oxidation to acetyl-CoA and entry into TAC. uHMG-CoA synthase is the key enzyme in ketogenesis, uwhile succinyl-CoA transsulfurase and acetoacetate thiokinase are the key enzymes in ketolysis. uOverproduction of ketone bodies in uncontrolled diabetes can lead to ketosis.  Practice The process in which triacylglycrols strored in adipose tissue are degraded to fatty acids and glycerol is called ( ) or( ) fat moblization , lipolysis The key enzyme of lipolysis is ( ) hormone-sensitive lipase (HSL) ( ) carries long chain fatty acids across the inner mitochondrial membrane Carnitine  Four steps in one round of B-oxidation of FA are( ) ( )( )( ) Dehydrogenation Hydration Dehydrogenation Thiolysis Rate-limiting enzyme of B-oxidation of FA is ( ) carnitine acyltransferase Ⅰ Ketone bodies including( )( )( ) acetoacetate, β-hydroxybutyrate, acetone. Oxidation of Fatty Acids occurs in ( ) mitchondria  Effect of hormones on lipolysis The hormones stimulating lipolysis are called Lipolytic Hormones which including A epinephrine B norepinephrine C adrenocorticotropic hormone (ACTH) D thyroid stimulating hormone (TSH) E Glucagon l The hormones inhibiting lipolysis are called Antilipolytic Hormones. A insulin B prostaglandin E2 C nicotinic acid. D thyroid stimulating hormone (TSH) E Glucagon  Location for the formation of ketone bodies Is ( )of ( ) , the material is ( ), which come from ( ),Rate-limiting enzyme of ketogenesis is ( ) Mitochondria, liver acetyl CoA fatty acid oxidation HMG-CoA synthase Because the lack of ( ) and ( )in the liver. So the liveer can not utilize ketone bodies. these two enzyme are the key enzyme of ketolysis succinyl-CoA transsulfurase acetoacetate thiokinase The product of the β-oxidation ( )( ) ( ) FADH2, NADH, acetyl CoA,  Defination lLipolysis (fat mobilization） lHSL lKetone bodies lKetogenesis lKetolysis lLipolytic Hormones lAntilipolytic Hormones.  Practice 1、 Glycerophospholipids are lipids with a( )、 ( )、 ( ) 、( ) glycerol, fatty acids, phosphate group nitrogen containing base. 2、 There are two Pathways for the synthesis of Glycerophospholipids , they are( ) and ( ) CDP-diacylglycerol pathway, Diacylglycerol pathway 3、 phosphotidyl ethanolamine , Phosphotidyl choline are synthesized by( ) Diacylglycerol pathway 4、 Phosphatidylinositol , phosphatidylserine , And Cardiolipin are synthesized by ( ) CDP-diacylglyeerol pathway 5、Degradation of glycerophospholipids by( ) phospholipase 6、 During the synthesis of phosphotidyl ethanolamine ,Phosphotidyl choline , Choline and ethanolamine must be activated to ( ) and( ) CDP- choline CDP- ethanolamine. 7、 the bond between phosphate and nitrogen containing compound of Phosphatidylinositol was hydrolyzed by( ) Phospholipase D 8 Phospholipid was hydrolyzed by PLA1 , produce ( ) and ( ) lysophospholipid 2, free fatty acidd  Blood lipid exist and transport in the form of ( ) lipoprotein. Protein constituents of lipoprotein particles are called ( ) apolipoproteins(apo). By Electrophoresis method , lipoprotein can be classified into ( )( )( )( ) - Lipoprotein pre -Lipoprotein -Lipoprotein CM (chylomicron) By Ultracentrifuge method , lipoprotein can be classified into ( )( )( )( ) CM\ VLDL \ LDL\ HDL u( ) transports lipids resulting from digestion and absorption CM u ( )transport triacylglycerol from the liver VLDL u( )deliver cholesterol from liver to other tissue LDL u( )remove cholesterol from the tissues in the process known as reverse cholesterol transport HDL  Cholesterol and cholesterol ester are the predominant lipids in( ) A CM B VLDL C LDL D HDL E - Lipoprotein C  LDL contain only ( ) A apoB100 B apoB48 C apoCⅡ、 D apoCⅢ E apoE； A  CM contain a lot of apoprotein, ( ) is unique to CM. A apoB100 B apoB48 C apoCⅡ、 D apoCⅢ E apoE； B ( )contains most protein A CM B VLDL C LDL D HDL E - Lipoprotein D ( )activates lipoprotein lipase（LPL） A apo A II B apo A I C apo CⅡ、 D apoCⅢ E apoE； C ( )activates LCAT A apo A II B apo A I C apoCⅡ、 D apoCⅢ E apoE； B  Write out the Functions of apolipoproteins 1) To combine and transport lipids 2) to stabilize the structure of lipoprotein. 3) Some of them are enzyme cofactors, 4) Some of them act as ligands which interact with lipoprotein receptors in tissue.  ( )carries endogenous triglycerides from liver to peripheral tissues for energy needs. VLDL ( )transport cholesterol from liver to the peripheral tissues. LDL ( ) transport cholesterol from peripheral tissues to liver (RCT) HDL  Definition of RCT The transport of cholesterol from the peripheral tissues to the liver is known as reverse cholesterol transport (RCT). 5. What is essential amino acids , which amino acid belong to essential amino acids. v Definition : the amino acids which the body cannot make at all or cannot make enough to meet physiological needs, and must be supplied in the diet are called nutritionally essential amino acids. v 8 essential amino acid: isoleucine, leucine, lysine, methionine, phenylalanine, threonine , tryptophan and valine. 6. Which is the primary proteolytic enzyme in the stomach? Pepsin 7. What is Endopeptidase the enzyme that cleave internal peptide bonds,forming shorter peptides. Contain: Trypsin ,chymotrypsin, and elastase 8.What is exopeptidase which remove amino acids from the amino terminus or carboxyl terminus contain : carboxypeptidase and aminopeptidase 9. The absorption mechanism of amino acid some amino acids requires the active transport While others are absorbed via the facilitated diffusion γ-glutamyl cycle 10.What is putrefaction ? the proteins undigested and digestion products not absorbed in the process of digestion , which will be used by bacteria in the large intestine, this process is called putrefaction 11. Tyrosine is converted to ( )by decarboxylation ? histidine to histimine lysine to cadaverine tryptophan to tryptamine tyrosine to tyramine phenylalanine to phenylethylamine 12. Decreasing the pH value will ( ) the absorption of ammonia decrease 13 what is protein turnover? The constant recycling of proteins in the body is known as protein turnover. 14. What is half-life? t1/2, the time required to reduce the concentration of proteins to 50% of its initial value. 15. What is amino acid pool? amino acid released by hydrolysis of tissue protein are mixed with those digested and absorbed from protein foods ,all of these amino acids are distributed throughout the body and collectively constitute the amino acid pool 16. Two major pathway of degradtion proteins (1) ATP-independent process: (2) ATP-dependent process: 17. The process of ATP-dependent process: 1) ubiquitination : 2) degradation in proteasome  Questions 1. The ways for deamination: transamination oxidative deamination combined deamination transamination combined oxidative deamination transamination combined purine nucleotide cycle 2. The prosthetic group of transaminase is ( ) , come from( ), as a coenzyme Which is act as ( ) in transamination reactions, pyridoxal phosphate (PLP vitamin B6 facilitating the 3. Write out the transamination reaction transfer of amino groups between catalyzed by GOT and GPT amino acids and α-keto acids.  4. Why Some Transaminase are of diagnositc value? Transaminases are normally intracellular enzyme. physical trauma or a disease process can cause cell lysis, resulting in release of intracellular enzymes into the blood.So the mensuration of serume transaminase can help the doctor to diagnosis the disease 5. the oxidative deamination is catalyzed by ( ) glutamate dehydrogenase. 6.The most important manner for the removal of amino group is ( ) , transamination reactions. 7. The reaction site of urea cycle. liver 8. The energy needed in the urea cycle. provided by ATP and the hydrolysis of ATP during various 9. The nitrogen materials of urea. come from steps of the cycle. ammonia (NH3) 10.What is hyperammonemia. A block in any of the urea cycle enzymes leads to an increase in the amount of ammonia in the blood ,so called hyperammonemia 11. The reason of hyperammonemia? the most common cause is a genetic defect of urea synthesis enzymes. 12. the totally reaction of urea cycle? uFormation of carbamoyl phosphate uFormation of citrulline uFormation of argininosuccinate uFormation of arginine uFormation of urea  13. transamination combined oxidative deamination take place in the ( ) mitochondria. transamination combined purine nucleotide cycle take place in ( ), because ( ) cytosol, because the enzymes involved in the purine nucleotide cycle are located in the cytosol.  Questions : 1. the catabolism of the carbon skeletons of AA converges to form seven products, they are 1) pyruvate, 2) acetyl CoA, 3) acetoacetyl CoA, 4)α-ketoglutarate , 5) succinyl CoA, 6) fumarate , 7) oxaloacetate. 2. Amino acids are grouped into 3 classes Glucogenic Ketogenic Glucogenic and ketogenic  3. What is Glucogenic AA Glucogenic: Amino acids are termed as glucogenic if their carbon skeletons can give rise to the net synthesis of glucose. 4. What is Ketogenic AA Ketogenic : Amino acids are termed as ketogenic if their carbon skeletons can give rise to the net synthesis of ketone bodies. 5. What is Glucogenic and Ketogenic AA  6 Ketogenic amino acid include : 7. There are three sulfur-containing amino acids : methionine, cystine, cysteine. 8. the direct donor of methyl group is ( ) the indirect donor of methyl group is ( ) SAM, the N5-methyl-FH4 9. Aromatic amino acid include: phenylalanine , tyrosine, tryptophan 10.Phenylketonuria Caused by the absence or deficiency of ( ) phenylalanine hydroxylase  11. Write down the metabolism pathway of use aspartate to synthesis glucose. GOT Aspartate +а-ketoglutarate Oxaloacetate +glutmate PEP carboxykinase Reverse of glycolysis Oxaloacetate PEP ATP ADP Fuctose -1,6-biphosphatase Fuctose -1,6-biphosphate Fuctose -6-phosphate glucose-6-phosphatase glucose-6-phosphate glucose  12.Write down the thoroughly breakdowm metabolism pathway of alanine, and calculate how many ATP can produced by alanine.  13. How alanine oxidized thoroughly , and how many ATPs can be produced. Write down the main reaction, and calculate ATPs 1. Alanine + α-Ketoglutarate ALT Pyruvate + glutamate 2. Pyruvate Pyruvate dehydrogenase Acetyl - CoA NAD + NADH NADH go into respiratory chain and oxidized produce 3 ATPs 3. Acetyl CoA go into TCA cycle , produce 12 ATPs so , totally 15 ATPs are produced per alanine oxidized  14. How aspartate oxidized thoroughly , and how many ATPs can be produced. Write down the main reaction, and calculate ATPs GOT 1 Aspartate +а-ketoglutarate Oxaloacetate +glutmate PEP carboxykinase 2 Oxaloacetate PEP ATP ADP Pyruvate kinase 3 PEP Pyruvate ADP ATP 4 Pyruvate dehydrogenase Pyruvate Acetyl - CoA NAD + NADH NADH go into respiratory chain and oxidized produce 3 ATPs 5. Acetyl CoA go into TCA cycle , produce 12 ATPs so , totally 15 ATPs are produced per aspartate oxidized 15 ( ) is active methionine, serves as major methyl group donor of in biological reaction S-Adenosyl methionine or SAM 16. ( ) is the donor of sulfate in vivo in the reaction such as biotransformation. PAPS  Questions : 1. Creatin is produced from ( ) ( ) and ( ) glycine, arginine and methionine 2. Creatin is used for( ) in muscle and brain tissue energy storage 3. γ-aminobutyrate is produced from( ) by decarboxylation Glutamate 4. taurine is produced from( ) by decarboxylation cystein 5. Catecholamines are produced from ( ) tyrosine  6. What is one carbon unit ? During the catabolism of amino acid ,some functional group contained only one molecule of carbon element will be got , which are called-------- one carbon unit 6. Which is not one carbon unit ? CH3 , CH2 , CH , CH=NH , CHO , CO2 7. the carrier of one carbon unites is ( ) FH4/THF 8.Four kinds of amino acids are the major sources of one carbon in the body,They are Serine, Glycine , Histidine and Tryptophan  Questions : 1. Biological function of nucleotide 1 They are the precursors for DNA and RNA synthesis. 2 They are served as carriers of the activated intermediates in the synthesis of some carbohydrates,lipids and protein, eg, UDPG, SAM. 3 Components of some essential coenzyme.such as FAD, NAD+,NADP+, 4 pattern of energy utilization in vivo. ATP is basic energy substance in body. 5 regulatory molecules , cAMP and cGMP play important role in signal transduction as second messengers. 2. The sources of nitrogen and carbon atoms of the purine ring CO2 Glycine Aspartate N10-CHO-FH4 N10-CHO-FH4 Glutamine 3. Three process contribute to purine nucleotide biosynthesis de novo synthesis : Synthesis from amphibolic intermediates salvage synthesis: phosphoribosylation of purines phosphorylation of purine nucleosides 4. What is de novo synthesis of purine nucleotides De novo synthesis of purin nucleotides is a metabolic pathway in which purine nucleotides are synthesized by a series of enzymatic reactions with ribose phosphate, amino acid, one-carbon unit and CO2 as materials. 5. What is salvage synthesis of purine nucleotides Salvage synthesis pathway is the pathway in which purines, purine ribonucleosides are converted to mononucleotides. 6. Characteristics of the de novo synthesis of purine nucleotides 1) purine nucleotides is synthesized step by step on the basis of R-5-P. 2)Purine base is not synthesized first 3) biosynthesis of IMP need 5 ATP and 6 high-energy bond。 4)the synthesis of AMP or GMP needs one more ATP or GTP。 7. physiological significance of salvage synthesis pathway l Salvage synthesis pathway requires far less energy than dose de novo synthesis , so save energy and amino acids l Some tissues and organs such as brain and bone marrow can only carry out salvage reaction  8. in de novo synthesis of purin nucleotides, ( ) is synthesized first, and then ( ) and ( )is sytnhesized. phosphoribosyl pyrophosphate (PRPP) inosine monophosphate AMP (adenosine (IMP) monophosphate) / 9. de novo synthesis take place in ( ). Cytosol of liver GMP (guanosine monophosphate) is synthesized. 10. deoxynucleotides are not synthesized from the beginning, but are formed from ( ). ribonucleotides. 11. Analogs of purine nucleotide is ( ) 12. Analogs of glutamine is ( ) 13.MTX is the analogue of ( ) inhibit ( ) so influence the metabolism of one carbon unit. 6-MP (6- merca Cytosol of liver NDP 6-MP Azaserine ptopuri ne). Folic acid dihydrofolate reductase 13 purines in humans are catabolized to ( ) 14.( ) is a metabolic disorder of purine catabolism , 15. ( )is used for the therapy of gout ,it can inhibit ( ) uric acid gout Allopurinol Xanthine oxygenase 1. What is de novo synthesis pathway of pyrimidine nucleotides utilizing phosphoribose, amino acid, one carbon unit , CO2 etc. as materials and series of enzymes as catalyst to synthesize pyrimidine organisms. 2. the difference between CPSⅠ and CPSII CPSⅠ CPSII distribution in mitochondrium in cytosol Nitrogen NH3 glutamine activator N-AGA non Function synthesis of urea synthesis of pyrimidine  3.element sources of pyrimidine base Carbamoyl Gln asparate phosphate CO2 4. in de novo synthesis of pyrimidine nucleotides ( ) is synthesized first, and then ( ) and ( )is synthesized. 5. Analog of pyrimidine is ( ) 6.De novo synthesis of pyrimidine take place in ( ) 7( ) is the methyl donor of TMP UMP , CMP , dTMP Cytosol 5-FU, N5, N10-CH2-FH4  Questions 1. What is biotransformation? Definition : biotransformation is the process of the chemical alteration of some nonnutritive substance by metabolic reaction in vivo 2. ( liver ) is the main organ for biotransformation 3. Biotransformation have two phase reaction , In Phase 1: ( ),( )( ) Phase 2: ( ) Conjugation Oxidation, Reduction, and Hydrolysis  4. The main enzyme take part in oxidation reactions: monooxygenase monoamine oxidase(MAO) alcohol dehydrogenase (ADH) aldehyde dehydrogenase (ALDH) 5. The main enzyme take part in reduction reactions: nitroreductase azoreductase 6. In conjugation reaction, donor of glucuronyl is ( ) donor of sulfate is ( ),donor of CH3 is ( ), 1. UDPGA (Uridine 5’-diphosphate-glucuronic acid) 2. PAPS (3’-Phosphoadenosine-5’-phosphosulfate) 3. SAM (S-Adenosyl methionine) 7.The Factors affect the activity of the enzymes disease Inducers Inhibitors Differ among species Differ among individuals Vary according to age and sex  Questions 1. Heme is synthesized with( ) and ( )as two starting materials. The( ) iron incorporated after the protoporphyrin has been assembled succinyl-CoA glycine ferrous 2. For synthesis heme, the major site is ( ), The initial reaction and the last three steps occur in( ) , the intermidiate steps occur in the ( ) liver mitochondria, cytosol 3. In the process of heme synthesis, ( ) is the rate-limiting enzyme ALA synthase 4. Catabolism of heme produces( ) bilirubin 5. Bilirubin is transported in blood by binding with ( ) albumin 6. in the liver bilirubin conjugate with( ), mainly form( ) UDPGA Bilirubin diglucuronide 7. Conjugated bilirubin is reduced to ( ) by intestinal bacteria, then excreted in the feces urobilin 8. Conjugated bilirubin is also called ( ) unconjugated bilirubin is called ( ) direct reacting bilirubin; indirect reacting bilirubin” 9. What is jaundice? refers to the yellow color of the skin and sclera caused by deposition of bilirubin. 10.Classificaiton of jaundice are ( ),( ),( ) Hemolytic jaundice Hepatocellular jaundice Obstructive jaundice 11 whati is urobilinogen enterohepatic circulation ? In intestin , small fraction of the urobilinogens is reabsorbed and enters liver through portal vein.Most of these urobilinogens will be reexcreted into intestinal tract along with bile, so to form the urobilinogen enterohepatic circulation 13 , which is not the donor of conjugation reaction during biotransformation? A. UDPGA B.UDPG C.acetyl-CoA D.PAPS E.SAM  Study questions The base sequence of one strand in a DNA molecular is 5’-AACGT-3’,the sequence of the opposite strand is: A: ACGTT B: UUGCA C: AACGT D: TTGCA E: ACGTT Answer: E Liaoning Medical University [email protected]  Study questions Which of the following bond link the nucleotide in the primary structure of nucleic acid? A. peptide bond B. hydrogen bond C. 3′,5′-phosphodiester bond D. salt bond E. hydrophobic bond Answer: C Liaoning Medical University [email protected]  Which of the following nucleotide is not in DNA molecule ? A.dAMP B.dGMP C.dTMP D.dUMP E. dCMP Answer: D Liaoning Medical University [email protected]  Which of the following is the common component of DNA and RNA? A.D-ribose B. D-2-desoxyribose C. uracil D. thymine E. guanine Answer: E Liaoning Medical University [email protected]  Which of the following is the secondary structure of DNA? A.α-helix B.β-folding C.supercoil D.β-turn E.double helix structure Answer: E Liaoning Medical University [email protected]  In DNA molecule, the adenine content is 15%，so the cytosine content is : A.0.15 B.0.3 C.0.4 D.0.35 E.0.07 Answer: D Liaoning Medical University [email protected]  A nucleotide consists of A. a sugar, a base and a phosphate B. a sugar and a phosphate C. paired bases D. a sugar, a base and three phosphates Answer: A Liaoning Medical University [email protected]  Nucleoside is a pyrimidine or purine base A. covalently bonded to a sugar B. ionically bonded to a sugar C. hydrogen bonded to a sugar D. none of the above Answer: A Liaoning Medical University [email protected]  Study questions Which of the following DNA has the lowest Tm? A.A-T is 15% B.G-C is 25% C.G-C is 40% D.A-T is 80% E. G-C is 55% Answer: D Liaoning Medical University [email protected]  Nucleic acids can absorb ultraviolet light. Which is the sharp absorb band A. 260 nm B. 280 nm C. 320 nm D. 450 nm Answer: A Liaoning Medical University [email protected]  Which of the following is correct about DNA denaturation? A. hydrogen bond between the complementary base pair cleavage B. the sequence of basic group is destroyed C. DNA denaturation is irreversible D. character of light absorption disappear E. A260 is degraded Answer: A Liaoning Medical University [email protected]  Study questions Which of the following is the common sequence of tRNA 3' end? A.CCA B.CAA C. CCC D.AAC E.AAA Answer: A Liaoning Medical University [email protected]  Explain the terms: DNA denaturation; hyperchromic effect; Ribozymes Questions: 1．Please explain briefly the difference between RNA and DNA. 2．What is Tm? Write out the factors that affect the Tm. 3 ． Please state the structure characters of eukaryotic mRNA. 4．There are how many RNA in cell? Please write out the RNA and the function of the different RNA. 5. What are the characters of double helix of DNA? Liaoning Medical University [email protected] 1.The rate-limiting step of fatty acid synthesis is catalyzed by: A.acetyl-CoA carboxylase B. ATP-citrate lyase C.malic enzyme D. pyruvate dehydrogenase E.thiolase A.  2.Which is the key enzyme in the regulation of fatty acid synthesis? A.fatty acid synthase B.acetyl-CoA carboxylase C.keto-acyl-ACP D.enoyl-ACP reductase E.thioesterasesynthase B.  3.NADPH in fatty acid synthesis comes from: A.aerobic oxidation of glucose B. glycolytic pathway C. gluconeogenesis D.pentose phosphate pathway E.glucuronate pathway D  4.Which is prosthetic group of acetyl-CoA carboxylase? A.NAD+ B.biotin C.NADP+ D.FAD E.FMN B.  5.Which is the pathway that acetyl-CoA is transported from the mitochondria into the cytosol to allow fatty acid synthesis to occur? A.TAC B.malate-asparate shuttle C. glucose pyruvate cycle D.citrate- pyruvate cycle E.α-glycerophosphate shuttle D  6.Which of following is the most important site to synthesize triacylglycerols? A.liver B.kindey C.adipose tissue D.brain E.intestine A 7 Which of the following are inhibitors of acetyl-CoA carboxylase? A.citrate B.cAMP C.CoA D.ATP E.acyl-CoA E  10.Which of following is not the product of fatty acid β-oxidation in liver? A.NADH+H+ B.FADH2 C.H2O D.acetyl-CoA E.acyl-CoA C  11.Which can transport acyl-CoA into the mitochondria? A.apolipoprotein B.lipoprotein C.albumin D.citrate E.carnitine E  13.How many mols of ATP are yielded when 1 mol palmitic acid (16 C) is oxidized to CO2 and H2O ? A.129 B.131 C.165 D.182 E.199 A  14.Which is not required in β-Oxidation of fatty acids? A.CoASH B.NADP+ C.carnitine D.FAD E.NAD+ B.  15.Which is the correct sequence of 4 reactions in fatty acids oxidation? A.oxidation,oxidation,hydration,thiolysis B.thiolysis,oxidation,oxidation,hydration C. dehydrogenation, hydration, dehydrogenation, thiolysis D.hydration,oxidation,thiolysis,oxidation E.oxidation,thiolysis,oxidation,hydration C.  16.Which is the rate –limiting enzyme in the TG degradation? A.HSL B.LPL C.DAG lipase D.HL E.MAG lipase A  17.Which hormone can accelerate fat mobilization? A.epinephrine B.glucagons C.TSH D.ACTH E. all above E  18.Which is anti-lipolytic hormone ? A.epinephrine B.glucagons C.TSH D.ACTH E.prostaglandin E2 E  19.Which is the key enzyme in β-oxidation of fatty acids? A.carnitine acyl transferaseⅠ B.carnitine acyl transferaseⅠ C.acyl-CoA synthetase D.carnitine-acylcaritine translocase E.acetyl-CoA carboxylase A  20.The following compounds are generated accompanying with fatty acids β －oxidation except: A.H2O B.acetyl-CoA C.acyl-CoA D. NADH+H+ E. FADH2 A  21.Acetyl-CoA produced during fatty acid mobilization in the liver can be mainly converted to: A.glucose B.cholesterol C.fat D.ketone bodies E.cholesterol ester D  22.In which following conditions are ketone bodies synthesis greatly accelerated? A.glycolysis is enhanced B.fat mobilization is enhanced C.fatty acid synthesis is enhanced D. malonyl-CoA is reduced E.aerobic oxidation of glucose is enhanced B  23.The lack of ( ) means that ketone bodies are synthesized exclusively in the liver and must be used elsewhere. A.HMGCoA synthase B.succinyl-CoA transsulfurase C.HMGCoA reductase D. acetoacetyl-CoA thiolase E.HMGCoA thiolase B Acetoacetate thiokinase  24.Which of following does not utilize ketone bodies? A.skeletal muscle B.heart C.brain D.liver E.kindey D  25.The direct precursor of acetoacetate in ketone body formation in live is: A.3-hydroxybutyrate B.acetoacetyl-CoA C.3-hydroxybutyral-CoA D. mevalonate(MVA) E.HMGCoA E  26.Which of followings will raise in blood in long starvation？ A.glucose B.hemoglobin C.ketone bodies D.lactic acid E.pyruvate C  27.Which of followings is involved in ketolysis at extrahepatic tissues? A.oxaloacetate B.succinyl-CoA C.malonyl-CoA D.acyl-CoA E.pyruvate B  28.Energy for brain in long starvation mainly comes from: A.glucose oxidation B.lactate oxidation C.fatty acids oxidation D.ketone bodies oxidation E.amino acids oxidation D  29.The key enzyme of ketogenesis is: A.HMGCoA synthase B.HMGCoA reductase C. HMGCoA lyase D.acetoacetyl-CoA thiolase E.acetoacetyl-CoA thiokinase A  30.Ketone bodies include: A.β-hydroxybutyrate and oxaloacetic acid B.pyruvate and acetoacetate C.pyruvate and oxaloacetic acid D.acetone and β- hydroxybutyrate E.lactic acid and acetoacetate acetoacetate, β-hydroxybutyrate, and acetone. D  32.Which is not concerned with the glycerophospholipid biosynthesis? A.serine B.GTP C.ATP D.CTP E.choline B  33.Which is essential fatty acid? A.stearic acid B.oleic acid C.linoleic acid D.palmitic acid E.oxaloacetic acid Linoleic acid, linolenic acid arachidonic acids C  34.Choline is activated in the form of ( ), before it enters diacylglycerol pathway. A.ADP-choline B.UDP-choline C.CDP-choline D.GDP-choline E.CMP-choline C  36.Which of followings is indispensable in synthesis of glycerolphospholipids A.CTP B.UTP C.GMP D.UMP E.TDP A  37.Which is not concerned with the cholesterol biosynthesis? A.acetyl-CoA B.HMGCoA C.NADPH+H+ D.NADH +H+ E.ATP D  38.The raw material of cholesterol in the body is: A.pyruvate B.oxaloacetate C.malate D.acetyl-CoA E.α-ketoglutarate D  39.Which of following does not come from cholesterol? A.bile acid B.epinephrine C. glucocorticoids D.sex hormone E. vitamin D3 B  40.The most important mechanism for degrading and eliminating cholesterol is: A.conversion to sex hormone B. conversion to steroid hormones C. conversion to vitamin D3 D.synthesis of the bile acids E. conversion to urea D  42.Which is an intermediate on the pathway for synthesis of ketone bodies and cholesterol? A.malonyl-CoA B.acetoacetyl-CoA C.HMG-CoA D.acetyl-CoA E.acetoacetate C  43.In the liver,( ) is the rate–limiting enzyme on the pathway for synthesis of cholesterol. A.HMGCoA reductase B.HMGCoA synthase C.HSL D.LCAT E.ACAT A  44.The major place for cholesterol biosynthesis is: A.brain B.liver C.mature red blood cell D.kidney E.heart B  46.The sub-cell site of cholesterol synthesis is: A.mitochondria + lysosome B. mitochondria + Golgi body C. cytosol+ endoplasmic reticulum D. lysosome + endoplasmic reticulum E. cytosol+ Golgi body C  48.The major function of HDL is: A.to carry exogenous TG and CE from the intestine to the tissues B.to transport endogenous TG from the intestine to the tissues C.to transport endogenous cholesterol from the liver to the tissues D.to transport free fatty acid E.reverse cholesterol transport E  49.Which is the specific function of apoAⅠ ? A.activates LPL B.inhibits HL C.activates LCAT D.inhibits LCAT E.activates ACAT C  50.Which is the primary carrier of cholesterol in the blood of humans? A.CM B.HDL C.VLDL D.LDL E.IDL D  51.Which lipoprotein contains apoB48 mostly? A.HDL B.LDL C.VLDL D.CM E.IDL D  52.Which is the major form that transports endogenous TAGs from the liver to the tissues? A.HDL B.LDL C.VLDL D.CM E.IDL C  53.Which is the major form that participates in the reverse cholesterol transport? A.IDL B.HDL C.LDL D.VLDL E.CM B  54.ApoC Ⅰ activates: A.LPL B.LCAT C.ACAT D.HL E.HSL A  55.Based on density and size, plasma lipoproteins can be classified into four main groups,except: A.CM B.VLDL C.LDL D.HDL E.albumin E  56.The enzyme which esterifies cholesterol in cytosol is: A.lipoprotein lipase B.LCAT C.ACAT D. acyltransferase E.hepatic lipase C  57.The enzyme which esterifies cholesterol in blood plasma is: A.phosphatidase B.LCAT C.ACAT D.carnitine acyltransferase E.lipoprotein lipase B  58.Which of followings is the carrier of free fatty acids in blood? A.lipoprotein B.glycoprotein C.albumin D.globulin E.apolipoprotein C  59.Which of following runs fast in electrophoresis? A.HDL B.LDL C.VLDL D.CM E.IDL A  61.Which is the major form that transports exogenous TAGs to the circulation? A.HDL B.LDL C.VLDL D.CM E.IDL D  62.Acetyl-CoA carboxylase catalyzes the first committed step in the biosynthesis of fatty acids. which of the following are stimulators of the enzyme? A.citrate B.AMP C.palmitoyl-CoA D. isocitrate E.malonyl-CoA AD  64.The sub-cell of stearic acid synthesis includes: A.mitochondria B.peroxisome C.cytosol D.endoplasmic reticulum E.nucleus ACD  65.Which of followings is correct about acetyl-CoA carboxylase? A.is a regulatory allosteric enzyme B.is the key enzyme in lipogenesis C.contains a biotin as prosthetic group D.By phosphorylation make it inactive E.is regulated by phosphorylation/dephosphorylation ABCDE  66.The hormones stimulating lipolysis are called lipolytic hormones,which includ: A.glucagons B.insulin C.epinephrine D.ACTH E.prostaglandin E2 ACD  69.Utilization of ketone bodies in: A.heart B.brain C.kidney D.liver E.skeletal muscle ABCE  70.Ketone bodies are water-soluble fuels normally exported by the liver including: A.acetone B.pyruvate C.β-hydroxybutyrate D.acetoacetyl-CoA E. acetoacetate ACE  72.Which is essential fatty acid? A.oleic acid B.linolenic acid C. linoleic acid D.arachidonic acid E. palmitic acid BCD  73.Which of followings are the basic structure of glycerophospholipid? A.sphingosine B.fatty acids C. nitrogenous base D.glycerol E. ceramide BCD  74.Which of followings employ CDP- diacylglycerol pathway to synthesis themselves? A.phosphatidylinositol B.phosphatidyl ethanolamine C.phosphatidylserine D.cardiolipin E.phosphatidyl choline ACD  75.Which of followings are synthesized by diacylglycerol pathway? A.phosphatidylinositol B.phosphatidyl ethanolamine C. phosphatidylserine D.cardiolipin E.phosphatidyl choline BE  78.The raw materials in cholesterol biosynthesis are: A.acetyl-CoA B.NADPH C.ATP D.CO2 E.O2 ABC  80.Which of followings use acetyl-CoA as raw materials? A.cholesterol B.fatty acid C. pyruvate D. ketone bodies E.glucose ABD  82.The basic components of lipoprotein includes: A.cholesterol ester B.albumin C. phospholipid D.apolipoprotein E.triacylglycerol ACDE  85.The plasma lipoproteins which mainly transport triacylglycerols are: A.CM B.LDL C.VLDL D.HDL E.IDL AC 1.The rate-limiting step of fatty acid synthesis is catalyzed by: A.acetyl-CoA carboxylase B. ATP-citrate lyase C.malic enzyme D. pyruvate dehydrogenase E.thiolase A.  2.Which is the key enzyme in the regulation of fatty acid synthesis? A.fatty acid synthase B.acetyl-CoA carboxylase C.keto-acyl-ACP D.enoyl-ACP reductase E.thioesterasesynthase B.  3.NADPH in fatty acid synthesis comes from: A.aerobic oxidation of glucose B. glycolytic pathway C. gluconeogenesis D.pentose phosphate pathway E.glucuronate pathway D  4.Which is prosthetic group of acetyl-CoA carboxylase? A.NAD+ B.biotin C.NADP+ D.FAD E.FMN B.  5.Which is the pathway that acetyl-CoA is transported from the mitochondria into the cytosol to allow fatty acid synthesis to occur? A.TAC B.malate-asparate shuttle C. glucose pyruvate cycle D.citrate- pyruvate cycle E.α-glycerophosphate shuttle D  6.Which of following is the most important site to synthesize triacylglycerols? A.liver B.kindey C.adipose tissue D.brain E.intestine A 7 Which of the following are inhibitors of acetyl-CoA carboxylase? A.citrate B.cAMP C.CoA D.ATP E.acyl-CoA E  10.Which of following is not the product of fatty acid β-oxidation in liver? A.NADH+H+ B.FADH2 C.H2O D.acetyl-CoA E.acyl-CoA C  11.Which can transport acyl-CoA into the mitochondria? A.apolipoprotein B.lipoprotein C.albumin D.citrate E.carnitine E  13.How many mols of ATP are yielded when 1 mol palmitic acid (16 C) is oxidized to CO2 and H2O ? A.129 B.131 C.165 D.182 E.199 A  14.Which is not required in β-Oxidation of fatty acids? A.CoASH B.NADP+ C.carnitine D.FAD E.NAD+ B.  15.Which is the correct sequence of 4 reactions in fatty acids oxidation? A.oxidation,oxidation,hydration,thiolysis B.thiolysis,oxidation,oxidation,hydration C. dehydrogenation, hydration, dehydrogenation, thiolysis D.hydration,oxidation,thiolysis,oxidation E.oxidation,thiolysis,oxidation,hydration C.  16.Which is the rate –limiting enzyme in the TG degradation? A.HSL B.LPL C.DAG lipase D.HL E.MAG lipase A  17.Which hormone can accelerate fat mobilization? A.epinephrine B.glucagons C.TSH D.ACTH E. all above E  18.Which is anti-lipolytic hormone ? A.epinephrine B.glucagons C.TSH D.ACTH E.prostaglandin E2 E  19.Which is the key enzyme in β-oxidation of fatty acids? A.carnitine acyl transferaseⅠ B.carnitine acyl transferaseⅠ C.acyl-CoA synthetase D.carnitine-acylcaritine translocase E.acetyl-CoA carboxylase A  20.The following compounds are generated accompanying with fatty acids β －oxidation except: A.H2O B.acetyl-CoA C.acyl-CoA D. NADH+H+ E. FADH2 A  21.Acetyl-CoA produced during fatty acid mobilization in the liver can be mainly converted to: A.glucose B.cholesterol C.fat D.ketone bodies E.cholesterol ester D  22.In which following conditions are ketone bodies synthesis greatly accelerated? A.glycolysis is enhanced B.fat mobilization is enhanced C.fatty acid synthesis is enhanced D. malonyl-CoA is reduced E.aerobic oxidation of glucose is enhanced B  23.The lack of ( ) means that ketone bodies are synthesized exclusively in the liver and must be used elsewhere. A.HMGCoA synthase B.succinyl-CoA transsulfurase C.HMGCoA reductase D. acetoacetyl-CoA thiolase E.HMGCoA thiolase B Acetoacetate thiokinase  24.Which of following does not utilize ketone bodies? A.skeletal muscle B.heart C.brain D.liver E.kindey D  25.The direct precursor of acetoacetate in ketone body formation in live is: A.3-hydroxybutyrate B.acetoacetyl-CoA C.3-hydroxybutyral-CoA D. mevalonate(MVA) E.HMGCoA E  26.Which of followings will raise in blood in long starvation？ A.glucose B.hemoglobin C.ketone bodies D.lactic acid E.pyruvate C  27.Which of followings is involved in ketolysis at extrahepatic tissues? A.oxaloacetate B.succinyl-CoA C.malonyl-CoA D.acyl-CoA E.pyruvate B  28.Energy for brain in long starvation mainly comes from: A.glucose oxidation B.lactate oxidation C.fatty acids oxidation D.ketone bodies oxidation E.amino acids oxidation D  29.The key enzyme of ketogenesis is: A.HMGCoA synthase B.HMGCoA reductase C. HMGCoA lyase D.acetoacetyl-CoA thiolase E.acetoacetyl-CoA thiokinase A  30.Ketone bodies include: A.β-hydroxybutyrate and oxaloacetic acid B.pyruvate and acetoacetate C.pyruvate and oxaloacetic acid D.acetone and β- hydroxybutyrate E.lactic acid and acetoacetate acetoacetate, β-hydroxybutyrate, and acetone. D  32.Which is not concerned with the glycerophospholipid biosynthesis? A.serine B.GTP C.ATP D.CTP E.choline B  33.Which is essential fatty acid? A.stearic acid B.oleic acid C.linoleic acid D.palmitic acid E.oxaloacetic acid Linoleic acid, linolenic acid arachidonic acids C  34.Choline is activated in the form of ( ), before it enters diacylglycerol pathway. A.ADP-choline B.UDP-choline C.CDP-choline D.GDP-choline E.CMP-choline C  36.Which of followings is indispensable in synthesis of glycerolphospholipids A.CTP B.UTP C.GMP D.UMP E.TDP A  37.Which is not concerned with the cholesterol biosynthesis? A.acetyl-CoA B.HMGCoA C.NADPH+H+ D.NADH +H+ E.ATP D  38.The raw material of cholesterol in the body is: A.pyruvate B.oxaloacetate C.malate D.acetyl-CoA E.α-ketoglutarate D  39.Which of following does not come from cholesterol? A.bile acid B.epinephrine C. glucocorticoids D.sex hormone E. vitamin D3 B  40.The most important mechanism for degrading and eliminating cholesterol is: A.conversion to sex hormone B. conversion to steroid hormones C. conversion to vitamin D3 D.synthesis of the bile acids E. conversion to urea D  42.Which is an intermediate on the pathway for synthesis of ketone bodies and cholesterol? A.malonyl-CoA B.acetoacetyl-CoA C.HMG-CoA D.acetyl-CoA E.acetoacetate C  43.In the liver,( ) is the rate–limiting enzyme on the pathway for synthesis of cholesterol. A.HMGCoA reductase B.HMGCoA synthase C.HSL D.LCAT E.ACAT A  44.The major place for cholesterol biosynthesis is: A.brain B.liver C.mature red blood cell D.kidney E.heart B  46.The sub-cell site of cholesterol synthesis is: A.mitochondria + lysosome B. mitochondria + Golgi body C. cytosol+ endoplasmic reticulum D. lysosome + endoplasmic reticulum E. cytosol+ Golgi body C  48.The major function of HDL is: A.to carry exogenous TG and CE from the intestine to the tissues B.to transport endogenous TG from the intestine to the tissues C.to transport endogenous cholesterol from the liver to the tissues D.to transport free fatty acid E.reverse cholesterol transport E  49.Which is the specific function of apoAⅠ ? A.activates LPL B.inhibits HL C.activates LCAT D.inhibits LCAT E.activates ACAT C  50.Which is the primary carrier of cholesterol in the blood of humans? A.CM B.HDL C.VLDL D.LDL E.IDL D  51.Which lipoprotein contains apoB48 mostly? A.HDL B.LDL C.VLDL D.CM E.IDL D  52.Which is the major form that transports endogenous TAGs from the liver to the tissues? A.HDL B.LDL C.VLDL D.CM E.IDL C  53.Which is the major form that participates in the reverse cholesterol transport? A.IDL B.HDL C.LDL D.VLDL E.CM B  54.ApoC Ⅰ activates: A.LPL B.LCAT C.ACAT D.HL E.HSL A  55.Based on density and size, plasma lipoproteins can be classified into four main groups,except: A.CM B.VLDL C.LDL D.HDL E.albumin E  56.The enzyme which esterifies cholesterol in cytosol is: A.lipoprotein lipase B.LCAT C.ACAT D. acyltransferase E.hepatic lipase C  57.The enzyme which esterifies cholesterol in blood plasma is: A.phosphatidase B.LCAT C.ACAT D.carnitine acyltransferase E.lipoprotein lipase B  58.Which of followings is the carrier of free fatty acids in blood? A.lipoprotein B.glycoprotein C.albumin D.globulin E.apolipoprotein C  59.Which of following runs fast in electrophoresis? A.HDL B.LDL C.VLDL D.CM E.IDL A  61.Which is the major form that transports exogenous TAGs to the circulation? A.HDL B.LDL C.VLDL D.CM E.IDL D  62.Acetyl-CoA carboxylase catalyzes the first committed step in the biosynthesis of fatty acids. which of the following are stimulators of the enzyme? A.citrate B.AMP C.palmitoyl-CoA D. isocitrate E.malonyl-CoA AD  64.The sub-cell of stearic acid synthesis includes: A.mitochondria B.peroxisome C.cytosol D.endoplasmic reticulum E.nucleus ACD  65.Which of followings is correct about acetyl-CoA carboxylase? A.is a regulatory allosteric enzyme B.is the key enzyme in lipogenesis C.contains a biotin as prosthetic group D.By phosphorylation make it inactive E.is regulated by phosphorylation/dephosphorylation ABCDE  66.The hormones stimulating lipolysis are called lipolytic hormones,which includ: A.glucagons B.insulin C.epinephrine D.ACTH E.prostaglandin E2 ACD  69.Utilization of ketone bodies in: A.heart B.brain C.kidney D.liver E.skeletal muscle ABCE  70.Ketone bodies are water-soluble fuels normally exported by the liver including: A.acetone B.pyruvate C.β-hydroxybutyrate D.acetoacetyl-CoA E. acetoacetate ACE  72.Which is essential fatty acid? A.oleic acid B.linolenic acid C. linoleic acid D.arachidonic acid E. palmitic acid BCD  73.Which of followings are the basic structure of glycerophospholipid? A.sphingosine B.fatty acids C. nitrogenous base D.glycerol E. ceramide BCD  74.Which of followings employ CDP- diacylglycerol pathway to synthesis themselves? A.phosphatidylinositol B.phosphatidyl ethanolamine C.phosphatidylserine D.cardiolipin E.phosphatidyl choline ACD  75.Which of followings are synthesized by diacylglycerol pathway? A.phosphatidylinositol B.phosphatidyl ethanolamine C. phosphatidylserine D.cardiolipin E.phosphatidyl choline BE  78.The raw materials in cholesterol biosynthesis are: A.acetyl-CoA B.NADPH C.ATP D.CO2 E.O2 ABC  80.Which of followings use acetyl-CoA as raw materials? A.cholesterol B.fatty acid C. pyruvate D. ketone bodies E.glucose ABD  82.The basic components of lipoprotein includes: A.cholesterol ester B.albumin C. phospholipid D.apolipoprotein E.triacylglycerol ACDE  85.The plasma lipoproteins which mainly transport triacylglycerols are: A.CM B.LDL C.VLDL D.HDL E.IDL AC  1.Where does de novo synthesis of purine nucleotide mainly take place? A. thoracic gland B. small intestine C. liver D. spleen E. marrow C  2.Which of the following is first synthesized in the process of de novo synthesis of purine nucleotide? A.GMP B. AMP C. IMP D. ATP E. GTP C  3.Which of the following is the end production of purine nucleotide catabolic metabolism? A. urea B. creatine C. creatinine D. uric acid E. β-alanine D 4.Which of the following is the methyl group donor of TMP ? A. N10-CHO-FH4 B. N5，N10=CH-FH4 C. N5，N10-CH2-FH4 D. N5-CH3-FH4 E. N5-CH=NH-FH4 C 5.Which of the following is the enzyme that catalyze the synthesis of uric acid ? A. urate oxidase B. xanthine oxidase C. adenosine deaminase D. Guanosine deaminase E. nucleophosphatase B  6.Which of the following substance directly link nucleotide synthesis and glucose metabolism? A.glucose B. glucose-6-phosphate C. glucose-1-phosphate D. glucose-1,6-diphosphate E. ribose-5-phosphate E  7.Which of the following reaction need HGPRT(hypoxanthine guanine phosphoribosyltransferase) ? A.de nove synthesis of purine nucleotide B.de nove synthesis of pyrimidine nucleotide C.salvage synthesis of purine nucleotide D.salvage synthesis of pyrimidine nucleotide E.catabolism of pyrimidine nucleotide C  8.Which of the following is not the direct material of de novo synthesis of purine nucleotide ? A. glycine B. aspartate C. glutamate D. CO2 E. one carbon unit C  9.Which of the following is directly reduced, and produce dNDP? A.ribose B. ribonucleoside C.NM D. NDP E. NTP D  10.Which of the following does not directly inhibit the synthesis of purine nucleotide ? A. TMP B. IMP C. AMP D. GMP E. ADP A  11.Which of the following is the analogue of azaserine ? A.serine B. glycine C. aspartate D. glutamine E. asparagine D  12.Which of the following is the common material of IMP and UMP? A. asparagine B. ribose phosphate C. glycine D. methionine E. one carbon unit B  13.Which of the following is the direct precursor of dTMP ? A.dUMP B. TMP C. TDP D. dUDP E. dCMP A  15.Which of the following provide only one C atom for purine synthesis? A.CO2 B. glutamine C. glycine D. aspartate E. foric acid A  16.Which of the following atom of pyrimidine ring is provided by CO2? A.C1 B. C6 C. C5 D. C4 E. C2 E  17.Which of the following provide two N atoms for pyrimidine ring? A.glutamine and ammonia B. glutamine and glutamate C.glutamine and carbomoyl phosphate D. aspartate and carbomoyl phosphate E. aspartate and glutamate D  18.Which of the following provide CH3 for dTMP? A. SAM B. N5-CHO- FH4 C. N5-CH3-FH4 D. N5，N10-CH2-FH4 E. N5，N10-CH2=FH4 D  19.Which of the following is the common material for the synthesis of pyrimidine and purine nucleotide? A.fumarate B. glutamine C. folic acid D. asparagine E. glycine B  20.Which of the following amino acid totally participate in the synthesis of purine nucleotide? A.glycine B. aspartate C. glutamate D. glutamine E. asparagine A  21.Which of the following are materials for de novo synthesis of purine nucleotide? A.ribose phosphate B. CO2 C. one carbon unit D. glutamine and aspartate E. glycine