所屬科目:研究所、轉學考(插大)◆生物化學
1. When two carbohydrates are epimers: (A) one is a pyranose, the other a furanose. (B) one is an aldose, the other a ketose. (C) one is α conformation, the other in β conformation. (D) they differ only in the configuration around one carbon atom. (E) they rotate plane-polarized light in the same direction.
2. Isomers of sugar in which the position of ketone and aldehyde groups have been changed are called: (A) anomers. (B) diastereoisomers. (C) enantiomers. (D) epimers. (E) None of the above.
3. Chitin and agarose are (A) polysaccharides. (B) polypeptides. (C) polynucleotides. (D) lipids. (E) enzymes.
4. Which of the following is true about glycoprotein? (A) They can act in cell-cell recognition. (B) They can be found on the outer face of the cell membrane only. (C) O-liked oligosaccharides is attached to the amide nitrogen of an Asn residue. (D) A、B、C (E) A、B
5. Glycolysis is enhanced by (A) glucose-1-phosphate, (B) fructose-1,6-bisphosphate, (C) fructose-2,6-bisphosphate, (D) glucose-6-phosphate and fructose-1,6-bisphosphate, (E) fructose-1,6-bisphosphate and fructose-2,6-bisphosphate.
6. When a muscle is stimulated to contract aerobically, less lactic acid is formed than when it contracts anaerobically because: (A) glycolysis does not occur to significant extent under aerobic conditions. (B) muscle is metabolically less active under aerobic than anaerobic conditions. (C) the lactic acid generated is rapidly incorporated into lipids under aerobic conditions. (D) under aerobic conditions in muscle, the major energy-yielding pathway is the pentose phosphate pathway, which does not produce lactate. (E) under aerobic conditions, most of the pyruvate generated as a result of glycolysis is oxidized by the citric acid cycle rather than reduced to lactate.
7. In glycolysis, the NADH formed in the glyceraldehyde 3-phosphate dehydrogenase reaction in vigorously contracting muscle must be reoxidized to NAD+ if glycolysis is to continue. The most important reaction involved in the reoxidation of NADH is: (A) dihydroxyacetone phosphate=> glycerol 3-phosphate. (B) pyruvate=>lactate. (C) glucose 6-phosphate=> fructose 6-phosphate. (D) isocitrate=>α-ketoglutarate. (E) oxaloacetate=>malate.
8. The function of glycogen phosphorylase is (A) the conversion of glucose - I - phosphate to glucose-6-phosphate. (B) to break down ATP. (C) to catalyze the phosphorolysis of glucose-1-phosphate from glycogen molecules. (D) to inhibit the production of glucose-1-phosphate. (E) to stimulate the build up of glycogen.
9. Muscle glycogen cannot contribute directly to blood glucose levels because (A) muscle glycogen cannot be converted to glucose 6-phosphate. (B) muscle lacks phosphoglucoisomerase. (C) muscle contains no glucokinase. (D) muscle contains no glycogen phosphorylase. (E) muscle lacks glucose 6-phosphatase.
10. Which one of the following statements is not true: (A) Low blood glucose will promote dephosphorylation of pyruvate kinase. (B) ATP is an allosteric factor for controlling glycogen phosphorylase b. (C) The first step in glycogen breakdown does not require ATP. (D) Phosphorylated glycogen phosphorylase and glycogen synthase can both be dephosphorylated by the same phosphatase. (E) Complete breakdown of glycogen catalyzes by glycogen debranching enzyme.
11. Which of the reactions of the citric acid cycle listed below results in the formation of a high-energy phosphate compound? (A) succinate dehydrogenase. (B) succinyl CoA synthetase. (C) isocitrate dehydrogenase. (D) citrate synthase. (E)alpha-ketoglutarate dehydrogenase.
12. In eukaryotic cells, glycolysis occurs in the ____ and the TCA cycle reactions take place in ____ (A) mitochondria; mitochondria. (B) cytoplasm; mitochondria. (C) cytoplasm; cytoplasm. (D) mitochondria; ribosomes. (E) cytoplasm; ribosomes.
13. Which is not correct regarding the electron transport chain complex in mitochondria? (A) Cytochrome oxidase carries electrons from cytochrome c to oxygen. (B) Q cycle occurs through complex IV. (C) Succinate dehydrogenase is a subunit of complex II. (D) NADH: ubiquinone oxidoreductase is complex I.
14. The final reduced species in the electron transport chain is (A) H2O. (B) cytochrome c. (C) ubiquinone. (D) NADH. (E) O2.
15. During ATP synthesis protons move "down" their electrochemical gradient through (A) the Fo complex of ATP synthase. (B) the F1 complex of ATP synthase. (C) a proton channel protein. (D) CoQH2-cytochrome c reductase.
16. An important difference between respiratory inhibitors and uncouplers is that (A) uncouplers are toxic substances while respiratory inhibitors are not. (B) uncouplers do not inhibit electron transport while respiratory inhibitors do so. (C) the effect of respiratory inhibitors cannot be characterized spectroscopically while that of uncoupleds can. (D) none of the above.
17. Dinitrophenol (DNP) uncouples mitochondrial electron transport from oxidative Phosphorylation by (A) dissipating the proton gradient. (B) inhibiting cytochrome oxidase. (C) dissociating the Fo and F1 units of the ATP synthase complex. (D) binding irreversibly to ubiquinone. (E) blocking the adenine nucleotide carrier (ATP/ADP exchanger).
18. Photosynthetic organisms use which of the following molecules as a reductant? (A) H2O (B) Carbohydrate (C) molecular oxygen gas (D) C2O (E) N2
19. In photosynthesis, all of the following reactions are directly dependent on light except (A) carbon fixation. (B) synthesis of ATP. (C) electron transport. (D) removal of electrons from H2O.
20. Which of the following sequences correctly represents the flow of electrons during photosynthesis? (A) NADPH ⇨ O2 ⇨CO2 (B) H2O ⇨NADPH⇨ Calvin cycle (C) H2O ⇨electron transport chain⇨ O2 (D)NADPH ⇨chlorophyll⇨ Calvin cycle
21. Which compartment of chloroplasts becomes acidic when the electron transport system is operating? (A) Lumen inside the thylakoid sac. (B) Stroma. (C) Space between inner and outer membranes. (D) Thylakoid membranes. (E) Cytoplasm.
22. Amino acids are joined together by an amide linkage called a (A) protein bond. (B) disulfide bond. (C) acrylate bond. (D) peptide bond. (E) PTM bond.
23. which of the following α-amino acids has the highest absorbance at 280 nm? (A) Tyr (B) Trp (C) Gly (D) Glu (E) Phe
24. What is the main stabilizing force in the secondary structure of proteins (A) peptide bond. (B) hydrogen bond. (C) disulfide bond. (D) hydrophobic bond.
25. What is one unit of urea biosynthesized from? (A) two units of and one unit of CO2. (B) one unit of as well as one unit of carboxyl and amino groups of arginine. (C) one unit of , one carboxyl group of aspartate, and one unit of amino group of arginine. (D) one unit of , one carboxyl group of arginine, and one unit of amino group of aspartate. (E) one unit of , one unit of CO2 and one unit of amino group of aspartate.
26. Arginine is considered _____(A) Glycogenic. (B) Ketogenic. (C) Glycogenic and ketogenic. (D) Neither glycogenic nor ketogenic. (E) None of above.
27. Tryptophan is considered _____(A) Glycogenic. (B) Ketogenic. (C) Glycogenic and ketogenic. (D) Neither glycogenic nor ketogenic. (E) None of above.
28. A deficiency of the following enzyme can lead to phenylketonuria (A) Tyrosinase. (B) Creatine synthase. (C) Phenylalanine hydroxylase. (D) Phenylalanine (E) Cystathionine lyase.
29. Which set of compounds listed below can serve as precursors for heme? (A) Gly, succinyl-CoA. (B) Gily, propionyl-CoA. (C) Gly, acetic acid. (D) Biliverdin, CO, Fe. (E) Bilirubin, CO, Fe. (F) Gly, biliveridin.
30. Myoglobin and the subunits of hemoglobin have: (A) no obvious structural relationship. (B) very different primary and tertiary structures. (C) very similar primary and tertiary structures. (D) very similar primary structures, but different tertiary structures. (E) very similar tertiary structures, but different primary structures.
31. Which of the following lipids is not a saturated fatty acid? (A) lauric acid (B) linoleic acid. (C) myristic acid. (D) stearic acid. (E) arachidic acid.
32. Which of the following best describes the cholesterol molecule? (A) Nonpolar, charged. (B) Nonpolar, uncharged. (C) Amphipathic. (D) Polar, charged. (E) Polar, uncharged.
33. The primary storage form of lipid is _____ and it is normally stored in the _____. (A) Phospholipid; liver. (B) cholesterol; muscles. (C) monoacylglycerol; adipocytes (D) triacylglycerols; adipocytes. (E) triacylglycerols; liver.
34. Which of the following molecules or substances contain, or are derived from, fatty acids? (A) sphingolipids. (B) prostaglandins. (C) beeswax. (D) prostaglandins and sphingolipids (E) prostaglandins、sphingolipids and beeswax.
35. Aspirin inhibits the synthesis of which of the following sets of eicosanoids? (A) prostagland E2 and leukotriene A4. (B) thromboxane A2 and leukotriene C4. (C) prostaglandin F2 and thromboxane A2. (D) prostaglandin A2 and 5-hydroperoxyeicosatetraenoic acid (5-HPETE). (E) all of them.
36. Which of the following is on the surface of a lipoprotein particle? (A) cholesterol and phospholipids (B) cholesterol and triacylglycerol (C) cholesterol ester and phospholipids (D) cholesterol ester and triacylglycerol (E) phospholipids and triacylglycerol
37. All of the following statement associated with plasma lipoproteins are true EXCEPT: (A) They have a nonpolar core consisting of triacylglycerols and cholesterol esters. (B) VLDL is the vehicle that liver uses to deliver triacylglycerols to the periphery. (C) They are the only carriers of lipid-based energy in the blood. (D) LDL function is to carry cholesterol to tissues. (E) HDL functions by carrying cholesterol away from tissues.
38. Dietary lipids are "packaged" in the intestine into ____ for transport in the blood stream. (A) HDL, (B) IDL, (C) VLDL, (D) Chylomicrons, (E) LDL.
39. Which of the following protein binds to LDL receptor? (A) ApoAI. (B) ApoB-48. (C) ApoC-II. (D) ApoD (E) ApoE.
40. Which of the following conditions would most likely result in the accumulation of cholesterol in extrahepatic tissues? (A) a deficiency in lipoprotein lipase. (B) a deficiency in acyl CoA:cholesterol acyltransferase. (C) a deficiency in apoprotein A-I. (D) a high level of HDL. (E) a high level of lecithin -cholesterol acyltransferase.
(1) hydrolysis of peptide bonds on the carboxyl side of Lys and Arg. (AB) CNBr (cyanogen bromide). (AC) Edman reagent (phenylisothiocyanate). (AD) Sanger reagent (FDNB, fluorodinitrobenzene). (AE) dithiothreitol. (BC) ẞ-mercaptoethanol. (BD) chymotrypsin. (BE) trypsin. (CD) performic acid.
(2) cleavage of peptide bonds on the carboxyl side of Met.(AB) CNBr (cyanogen bromide). (AC) Edman reagent (phenylisothiocyanate). (AD) Sanger reagent (FDNB, fluorodinitrobenzene). (AE) dithiothreitol. (BC) ẞ-mercaptoethanol. (BD) chymotrypsin. (BE) trypsin. (CD) performic acid.
(3) cleavage of peptide bonds on the carboxyl side of Phe、Tyr and Tip.(AB) CNBr (cyanogen bromide). (AC) Edman reagent (phenylisothiocyanate). (AD) Sanger reagent (FDNB, fluorodinitrobenzene). (AE) dithiothreitol. (BC) ẞ-mercaptoethanol. (BD) chymotrypsin. (BE) trypsin. (CD) performic acid.
(4) breakage of disulfide (-S-S-) bonds.(AB) CNBr (cyanogen bromide). (AC) Edman reagent (phenylisothiocyanate). (AD) Sanger reagent (FDNB, fluorodinitrobenzene). (AE) dithiothreitol. (BC) ẞ-mercaptoethanol. (BD) chymotrypsin. (BE) trypsin. (CD) performic acid.
(5) determining the amino-terminal amino acid in a polypeptide.(AB) CNBr (cyanogen bromide). (AC) Edman reagent (phenylisothiocyanate). (AD) Sanger reagent (FDNB, fluorodinitrobenzene). (AE) dithiothreitol. (BC) ẞ-mercaptoethanol. (BD) chymotrypsin. (BE) trypsin. (CD) performic acid.
三、 Answer question 1. Name and outline of 5 different enzymes when you chew and ingest your breakfast.
2. How do the components and structure of cell membrane relate to the function of membranes relate to functions of membranes?
3. Compare and describe the roles of CO2 and H2O in cellular respiration and photosynthesis.
4. Explain how our body can convert excess carbohydrates in the diet fats. Can excess carbohydrates be converted to protein? What else must be supplied?
5. Describe the urea cycle and its function in human?
6. Explain what and why is the sickle cell anemia?