101年 - [無官方正解]101 國立嘉義大學_碩士班(乙組)招生考試試題_應用化學系：生物化學#146583

1. By adding SDS (sodium dodecyl sulfate) during the electrophoresis of proteins, it is possible to: (A) determine a protein’s isoelectric point (B) determine an enzyme’s specific activity (C) determine the amino acid composition of the protein (D) preserve a protein’s native structure and biological activity (E) separate proteins exclusively on the basis of molecular weight.

2. A repeating structural unit in a multimeric protein is known as a(n): (A) domain (B) motif (C) oligomer (D) protomer (E) subunit.

3. When oxygen binds to a heme-containing protein, the two open coordination bonds of Fe²⁺ are occupied by (A) one O atom and one amino acid atom (B) one O₂ molecule and one amino acid atom (C) one O₂ molecule and one heme atom (D) two O atoms (E) two O₂ molecules.

4. Which of the following parts of the IgG molecule are not involved in binding to an antigen? (A) Fab (B) Fc (C) Heavy chain (D) Light chain (E) Variable domain

5. How is trypsinogen converted to trypsin? (A) A protein kinase-catalyzed phosphorylation converts trypsinogen to trypsin (B) An increase in Ca²⁺ concentration promotes the conversion (C) Proteolysis of trypsinogen forms trypsin (D) Trypsinogen dimers bind an allosteric modulator, cAMP, causing dissociation into active trypsin monomers (E) Two inactive trypsinogen dimers pair to form an active trypsin tetramer.

6. Which of the following is not a reducing sugar? (A) Fructose (B) Glucose (C) Glyceraldehyde (D) Ribose (E) Sucrose.

7. In DNA sequencing by the Sanger (dideoxy) method (A) radioactive dideoxy ATP is included in each of four reaction mixtures before enzymatic synthesis of complementary strands (B) specific enzymes are used to cut the newly synthesized DNA into small pieces, which are then separated by electrophoresis (C) the dideoxynucleotides must be present at high levels to obtain long stretches of DNA sequence (D) the role of the dideoxy CTP is to occasionally terminate enzymatic synthesis of DNA where Gs occur in the template strands (E) the template DNA strand is radioactive

8. Which of the following contains an ether-linked alkyl group? (A) Cerebrosides (B) Gangliosides (C) Phosphatidyl serine (D) Platelet-activating factor (E) Sphingomyelin

9. A compound containing N-acetylneuraminic acid (sialic acid) is (A) cardiolipin (B) ganglioside GM2 (C) phosphatidylcholine (D) platelet-activating factor (E) sphingomyelin

10. Which of these statements about the composition of biological membranes is false? (A) In a given eukaryotic cell type (for example, a hepatocyte), all intracellular membranes have essentially the same complement of lipids and proteins (B) The carbohydrate found in membranes is virtually all part of either glycolipids or glycoproteins (C) The plasma membranes of the cells of vertebrate animals contain more cholesterol than the mitochondrial membranes (D) The ratio of lipid to protein varies widely among cell types in a single organism (E) Triacylglycerols are not commonly found in membranes

11. Ubiquitin is a (A) component of the electron transport system (B) protease (C) protein kinase (D) protein phosphorylase (E) protein that tags another protein for proteolysis

12. Which of the following does not involve cyclic AMP? (A) Regulation of glycogen synthesis and breakdown (B) Regulation of glycolysis (C) Signaling by acetylcholine (D) Signaling by epinephrine (E) Signaling by glucagon

13. During strenuous exercise, the NADH formed in the glyceraldehyde 3-phosphate dehydrogenase reaction in skeletal 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) glucose 6-phosphate  fructose 6-phosphate (C) isocitrate  -ketoglutarate (D) oxaloacetate  malate (E) pyruvate  lactate

14. An enzyme used in both glycolysis and gluconeogenesis is (A) 3-phosphoglycerate kinase (B) glucose 6-phosphatase (C) hexokinase (D) phosphofructokinase-1 (E) pyruvate kinase

15. The oxidation of 3 mol of glucose by the pentose phosphate pathway may result in the production of (A) 2 mol of pentose, 4 mol of NADPH, and 8 mol of CO2 (B) 3 mol of pentose, 4 mol of NADPH, and 3 mol of CO2 (C) 3 mol of pentose, 6 mol of NADPH, and 3 mol of CO2 (D) 4 mol of pentose, 3 mol of NADPH, and 3 mol of CO2 (E) 4 mol of pentose, 6 mol of NADPH, and 6 mol of CO2

16 Which of the below is not required for the oxidative decarboxylation of pyruvate to form acetyl-CoA? (A) ATP (B) CoA-SH (C) FAD (D) Lipoic acid (E) NAD+

17 The reaction of the citric acid cycle that produces an ATP equivalent (in the form of GTP) by substrate level phosphorylation is the conversion of (A) citrate to isocitrate (B) fumarate to malate (C) malate to oxaloacetate (D) succinate to fumarate (E) succinyl-CoA to succinate

18 What is the correct order of function of the following enzymes of  oxidation?
1. β-Hydroxyacyl-CoA dehydrogenase
2. Thiolase
3. Enoyl-CoA hydratase
4. Acyl-CoA dehydrogenase (A) 1, 2, 3, 4 (B) 3, 1, 4, 2 (C) 4, 3, 1, 2 (D) 1, 4, 3, 2 (E) 4, 2, 3, 1

19 Which substance is not involved in the production of urea from NH4+ via the urea cycle? (A) Aspartate (B) ATP (C) Carbamoyl phosphate (D) Malate (E) Ornithine

20 Antimycin A blocks electron transfer between cytochromes b and c1. If intact mitochondria were incubated with antimycin A, excess NADH, and an adequate supply of O₂, which of the following would be found in the oxidized state? (A) Coenzyme Q (B) Cytochrome a₃ (C) Cytochrome b (D) Cytochrome e (E) Cytochrome f

21. Which of the following is correct concerning the mitochondrial ATP synthase? (A) It can synthesize ATP after it is extracted from broken mitochondria (B) It catalyzes the formation of ATP even though the reaction has a large positive △G'° (C) It consists of F₀ and F₁ subunits, which are transmembrane (integral) polypeptides (D) It is actually an ATPase and only catalyzes the hydrolysis of ATP (E) When it catalyzes the ATP synthesis reaction, the G'° is actually close to zero

22. The enzymatic machinery to fix atmospheric N₂ into NH⁴⁺ is (A) a means of producing ATP when excess N₂ is available (B) composed of two key proteins, each containing iron (C) relatively stable when exposed to O₂ (D) specific to plant cells (E) unaffected by the supply of electrons

23. If a cell were unable to synthesize or obtain tetrahydrofolic acid (H4 folate), it would probably be deficient in the biosynthesis of (A) isoleucine (B) leucine (C) lysine (D) methionine (E) serine

24. One amino acid directly involved in the purine biosynthetic pathway is (A) alanine (B) aspartate (C) glutamate (D) leucine (E) tryptophan

25. Which of the following is a DNA sequence? (A) Coactivator (B) Corepressor (C) Enhancer (D) Inducer (E) Transactivator

26. Protein amino acid side chains can hydrogen bond in the major groove of DNA, and discriminate between each of the four possible base pairs. In which one of the following groups of amino acids can all three members potentially be used in such DNA-protein recognition? (A) Ala, Asn, Glu (B) Arg, Gln, Leu (C) Asn, Gln, Trp (D) Asn, Glu, Lys (E) Glu, Lys, Pro

27. Assuming that the average amino acid residue contributes 110 to the peptide molecular weight, what will be the minimum length of the mRNA encoding a protein of molecular weight 50,000? (A) 133 nucleotides (B) 460 nucleotides (C) 1,400 nucleotides (D) 5,000 nucleotides (E) A minimum length cannot be determined from the data given

28. Splicing of introns in nuclear mRNA primary transcripts requires: (A) a guanine nucleoside or nucleotide (B) endoribonucleases (C) polynucleotide phosphorylase (D) RNA polymerase II (E) small nuclear ribonucleoproteins (snurps)

29. Which mechanism is used to repair a thymidine dimer in DNA? (A) mismatch repair (B) base-excision repair (C) nucleotide-excision repair (D) direct repair (E) more than one is used for this type of lesion

30. The 5' → 3' exonuclease activity of E. coli DNA polymerase I is involved in (A) formation of a nick at the DNA replication origin (B) formation of Okazaki fragments (C) proofreading of the replication process (D) removal of RNA primers by nick translation (E) sealing of nicks by ligase action

II.Short Questions (40%)
1. A nonapeptide was determined to have the following amino acidcomposition: (Lys)2, (Gly)2, (Phe)2, His, Leu, Met. The native peptidewas incubated with 1-fluoro-2, 4-dinitrobenzene (FDNB) and thenhydrolyzed 2,4-dinitrophenylhistidine was identified by HPLC. Whenthe native peptide was exposed to cyanogen bromide (CNBr), anoctapeptide and free glycine were recovered. Incubation of thenative peptide with trypsin gave a pentapeptide, a tripeptide, andfree Lys. 2,4-Dinitrophenyl- histidine was recovered from thepentapeptide, and 2,4-dinitrophenylphenylalanine was recoveredfrom the tripeptide. Digestion with the enzyme pepsin produced adipeptide, a tripeptide, and a tetrapeptide. The tetrapeptide wascomposed of (Lys)2, Phe, and Gly. What is the native sequence?(10%)

2. The following data were obtained in a study of an enzyme known tofollow Michaelis- Menten kinetics: (3%)

The Km for this enzyme is approximately:

(1) Excitation of the chlorophyll a molecule at the reaction center

(2) Replacement of the electron in the reaction center chlorophyll

(3) Light excitation of antenna chlorophyll molecule

(4) Passage of excited electron to electron-transfer chain(5) Exit on transfer to neighboring chlorophyll

4. Yeast can metabolize D-mannose to ethanol and CO₂. In addition tothe glycolytic enzymes, the only other enzyme needed isphosphomannose isomerase, which converts mannose 6-phosphateto fructose 6-phosphate. If mannose is converted to ethanol and CO₂ by the most direct pathway, which of the compounds and cofactorsin this list are involved? (8%)
(A) Lactate (B) Acetaldehyde (C) Acetyl-CoA (D) FAD(E) Glucose 6-phosphate (F) Fructose 1-phosphate (G) Pyruvate(H) Lipoic acid ( I) Thiamine pyrophosphate (J) Dihydroxyacetonephosphate

Across
2. Technique that can pinpoint promoter locations.

5. Complex ________ produce two or more different mRNAs andpolypeptides.

8. Proteins necessay for the activity of RNA Pol II are ______ factors.

10. DNA-directed enzymes that require a DNA template and ATP, GTP, UTP,and CTP. (2 words)

11. The newly synthesized RNA molecules is the _______ transcript.

13. As in film editing, cutting, and _______ an RNA by one frame too few ortoo many can be devastating to the final product.

14. Molecule that carries the genetic message from the chromosome to theribosomes. (abbreviation name)

Down
1. Type of enzymes RNase P, for example.

3. _(AAAAAAAAAAAAAAAAAAAAAAA)4_OH(-3’), at least. (2 words)

4. These are lacking in histone genes but present in almost all othervertebrate genes.

6. Structural analog of deoxythymidine. (abbreviation name)

7. Adapter moleculae between mRNA and amino acids. (abbreviationname)

9. Not Saturday morning cartoon characters, but complexes containingRNA ans protein and important in Group III splicing reaction (abbreviationname)

12. Nucleic acid serving as a component of ribosomes. (abbreviation name)