武汉大学生命科学学院 2003-2004学年第一学期期末考试 《分子生物学》试卷 Final exam of molecular Biology Course(spring 2004) 年级 专业 学号 姓名 成绩 PART I: DESCRIPTION (2 points each) Your answer should describe what each item is and how it functions in the cell. Diagrams, structure and sequence information should be included in your answer, as necessary 1. Yeast artificial chromosome 2. RNA interference 3. Proteomics 4. Shine-Dalgarno sequence 5. Alternative splicing 6. Ribozyme 7. p-dependent termination 8. RNA ed iting 9. DNA lesions 10. Protein targeting PARTI: MULTIPLE CHOICES (I points each) Select the one best answer for each question 1. The catalytic activity for peptide bond formation(the peptidyl transferase activity)is located in the 1) RN of the large ribosomal subunit 2) leader sequence of the messenger RNA 3) RNA of the small ribosomal subun 4) proteins of the small ribosomal subunit 5) proteins of the large ribosomal subunit 2. Bidirectional and semi-conservative are two terms that refer to 1) transcription 2) translation 3) replication 4) all of the ab ove 3. The fact that most amino acids are specified by multiple codons is known as 2) the universality of the genetic code 3 codon bia 4) the anticodon hypothesis 5)the redundancy of the genetic code 4. RNa polymerase I is the eukaryotic enzyme responsible for:
武汉大学生命科学学院 2003－2004 学年第一学期期末考试 《分子生物学》试卷 Final exam of Molecular Biology Course (Spring 2004) 年级______ 专业________ 学号_________ 姓名_______成绩______ PART I: DESCRIPTION (2 points each) Your answer should describe what each item is and how it functions in the cell. Diagrams, structure and sequence information should be included in your answer, as necessary. 1. Yeast artificial chromosome 2. RNA interference 3. Proteomics 4. Shine-Dalgarno sequence 5. Alternative splicing 6. Ribozyme 7. -dependent termination 8. RNA editing 9. DNA lesions 10. Protein targeting PART II: MULTIPLE CHOICES (1 points each) Select the one best answer for each question. 1. The catalytic activity for peptide bond formation (the peptidyl transferase activity) is located in the: 1) RNA of the large ribosomal subunit. 2) leader sequence of the messenger RNA. 3) RNA of the small ribosomal subunit. 4) proteins of the small ribosomal subunit. 5) proteins of the large ribosomal subunit. 2. Bidirectional and semi-conservative are two terms that refer to: 1) transcription. 2) translation. 3) replication. 4) all of the above. 5) none of the above. 3. The fact that most amino acids are specified by multiple codons is known as: 1) the “wobble” phenomenon. 2) the universality of the genetic code. 3) codon bias. 4) the anticodon hypothesis. 5) the redundancy of the genetic code. 4. RNA polymerase I is the eukaryotic enzyme responsible for:
1) transcription of ribosomal RNA 2) transcription of transfer RNa and other small RNa species 3) transcription of messenger RNA 4) initiation of Okazaki fragment synthesis in DNA replication 5. Restriction enzymes can cleave Dna that is either single-stranded or double-stranded as long as it contains the appropriate recognition site 1)True 2)False 6. Information about the sequence of the coding region of a gene is best obtained from 1) aYaC clone 2) 3) a cDNA clone 4) the protein 7. A chromatography method that can be used specifically to purify proteins based on their 1) gel filtration chromatography 2) ion-exchange chromatography 3) DNA affinity chromatography 4) antibody aff unity chromatography 8. A nonsense mutation is a change in the dNa sequence that results 1) a small deletion or insertion 2) an amino acid change in the protein encoded by the gene 3) a premature stop codon 4) all of the above 9. A protein complex involved in degradation of proteins within the cell is known as the 1) ubiquitin/proteasome system 2) molecular chaperone 3 cha onin 4) ribosome 5) Krebs/TCa cycle 10. binds to the repressor and turn on the transcription of the structural genes in the I)CAMP 3)allolactose 4)CRP 11. Which of the following RNA species is involved in degradation of the mRNA containing complementary sequence 1)miRNA 2)SIRNA 3)tRNA 4)5S RNA 12. The genome sequencing projects are confirming the theory that genome size is directly
1) transcription of ribosomal RNA. 2) transcription of transfer RNA and other small RNA species. 3) transcription of messenger RNA. 4) initiation of Okazaki fragment synthesis in DNA replication. 5. Restriction enzymes can cleave DNA that is either single-stranded or double-stranded, as long as it contains the appropriate recognition site. 1) True 2) False 6. Information about the sequence of the coding region of a gene is best obtained from: 1) a YAC clone. 2) a genomic clone. 3) a cDNA clone. 4) the protein. 7. A chromatography method that can be used specifically to purify proteins based on their charge is: 1) gel filtration chromatography. 2) ion-exchange chromatography. 3) DNA affinity chromatography. 4) antibody affinity chromatography. 8. A nonsense mutation is a change in the DNA sequence that results in: 1) a small deletion or insertion. 2) an amino acid change in the protein encoded by the gene. 3) a premature stop codon. 4) all of the above. 5) none of the above. 9. A protein complex involved in degradation of proteins within the cell is known as the: 1) ubiquitin/proteasome system. 2) molecular chaperone. 3) chaperonin. 4) ribosome. 5) Krebs/TCA cycle. 10. ___binds to the repressor and turn on the transcription of the structural genes in the Lac operon. 1) cAMP 2) lactose 3) allolactose 4) CRP 11. Which of the following RNA species is involved in degradation of the mRNA containing complementary sequence 1) miRNA 2) siRNA 3) tRNA 4) 5S RNA 5) U3 snRNA 12. The genome sequencing projects are confirming the theory that genome size is directly
ortional to the number of genes contained within that genome. In other words, a ome that is 10 times as big will contains approximately 10 times as many protein coding genes 1)True 2)False 13. HeLa cells, derived from a human cervical carcinoma, are able to propagate indefinitely in culture and are therefore known as a(n) 1) tissue culture 2)tu 3)transgenic cell line 4)immortalized cell line 14. E. coli cells are smaller than yeast cells 2)False 15. Which of the following domains is not a dna bind ing domain 1) Proline- rich domains 2)Helix-turn helix domains 3)Zinc finger domains 16. The aminoacyl-tRNa synthetases distinguish between about 40 different shaped tRNA molecules in the cells 1)True 2) False PART III: SHORT QUESTIONS (8 points each) 1. How do bacterial replication start and accomplished Remember to include the proteins/enzymes and important dna sequence involved in this process 2. Design experiments to clone a yeast gene and express this gene in yeast 3. Below is the multiple cloning site(MCs)of the plasmid vector pUC 18 and the N-terminal and C-terminal sequence of protein X. Note that the MCS constitutes a part of the Lacz open reading frame. Suppose that you are going to clone the protein X gene into pUC18, so that your target gene is transcribed under the control of lacz promoter, and translated with the lacz gene to produce a fusion protein. You are requested to use BamHI and Pstl to the clone X gene, please add these restriction sites on the corresponding position of the X gene Remember to maintain the read ing frame of the X gene with the lacz gene (1)MCS of pUC18 Ecori Sacl Kpnl Smal BamHI Xbal Sa Pstl ACGAATTCG AGC TCG GTA CCC GGG GAT CCT CTA GAGTCG ACC TGC AGG CAT GCA Thr Asn SerSer Ser Val Pro Gly Asp Pro Leu Glu Ser Thr Cys Arg HisAla (2)N-terminal sequence of X gene ATG ACC CCU CAU AAC GGC GAC. (3)C-terminal sequence of X gene.. GAUAGU ACAGCU GCCAAGTAA … Asp Ser Thr Ala Ala Lys
proportional to the number of genes contained within that genome. In other words, a genome that is 10 times as big will contains approximately 10 times as many protein coding genes. 1) True 2) False 13. HeLa cells, derived from a human cervical carcinoma, are able to propagate indefinitely in culture and are therefore known as a(n): 1) tissue culture. 2) tumor. 3) transgenic cell line. 4) immortalized cell line. 14. E. coli cells are smaller than yeast cells. 1) True 2) False 15. Which of the following domains is not a DNA binding domain 1) Proline-rich domains 2) Helix-turn helix domains 3) Zinc finger domains 4) Basic domains 16. The aminoacyl-tRNA synthetases distinguish between about 40 different shaped tRNA molecules in the cells. 1) True 2) False PART III: SHORT QUESTIONS (8 points each) 1. How do bacterial replication start and accomplished. Remember to include the proteins/enzymes and important DNA sequence involved in this process. 2. Design experiments to clone a yeast gene and express this gene in yeast. 3. Below is the multiple cloning site (MCS) of the plasmid vector pUC18 and the N-terminal and C-terminal sequence of protein X. Note that the MCS constitutes a part of the LacZ open reading frame. Suppose that you are going to clone the protein X gene into pUC18, so that your target gene is transcribed under the control of LacZ promoter, and translated with the LacZ gene to produce a fusion protein. You are requested to use BamHI and PstI to the clone X gene, please add these restriction sites on the corresponding position of the X gene. Remember to maintain the reading frame of the X gene with the LacZ gene 4. (1) MCS of pUC18 EcoRI SacI KpnI SmaI BamHI XbaI SalI PstI ACGAAT TCGAGC TCG GTA CCC GGG GAT CCT CTA GAG TCG ACC TGC AGG CAT GCA Thr Asn Ser Ser Ser Val Pro Gly Asp Pro Leu Glu Ser Thr Cys Arg His Ala (2) N-terminal sequence of X gene. ATG ACC CCU CAU AAC GGC GAC… Met Thr Pro His Asn Gly Asp… (3) C-terminal sequence of X gene. …GAU AGU ACA GCU GCC AAG TAA … Asp Ser Thr Ala Ala Lys Lac Z
PART IV: MAJOR QUESTIONS (20 points each) 1: Please describe how an mRNA gene is transcribed, processed and translated in human cells. What are the possible mechanisms in regulating the expression of this gene 2 (20 points): A bacterium is found to metabolize a rare sugar produced by a plant that the bacteria grow on. However, the bacteria prefer glucose as the energy source. The problem is, if you want to finish this course with a sat isfied score, you must figure out the regulatory mechanism that the bacteria used to determine the sugar choice The gene involving in the rare sugar metabolism has been identified as fin3. You can use northern blot to analyze the expression of fun3 and use dNA footprinting to analyze the binding of proteins to the control elements of fiun3 gene. The following table shows the experimental results Glucose Rare sugar Levels of Binding of proteins presence presence fun3 RNA Protein a binds to the promoter region Protein C binds upstream of the promoter Protein a binds to the promoter region ++ Protein b binds to the promoter region Protein C binds upstream of the promoter Protein b binds to the promoter region 1. Please propose a mechanism to explain the above results. You should focus on the question"How does the expression of fin3 gene is tightly regulated so that it is only highly expressed when the rare sugar is the only carbon source". You must answer what proteins A, B and C are (8 points) 2. How is protein A regulated? (2 points) (1) glucose turns the repressor on (4)the rare sugar turns the repressor off 3. How is protein C regulated? (1)glucose turns the activator on (2)glucose turns the activator off (3)the rare sugar turns the activator on (4)the rare sugar turns the activator off 4. How could you make the bacteria always use the rare sugar as the energy source even in the presence of glucose?( 8 points)
PART IV: MAJOR QUESTIONS (20 points each) 1: Please describe how an mRNA gene is transcribed, processed and translated in human cells. What are the possible mechanisms in regulating the expression of this gene? 2 (20 points): A bacterium is found to metabolize a rare sugar produced by a plant that the bacteria grow on. However, the bacteria prefer glucose as the energy source. The problem is, if you want to finish this course with a satisfied score, you must figure out the regulatory mechanism that the bacteria used to determine the sugar choice. The gene involving in the rare sugar metabolism has been identified as fun3. You can use northern blot to analyze the expression of fun3 and use DNA footprinting to analyze the binding of proteins to the control elements of fun3 gene. The following table shows the experimental results Glucose presence Rare sugar presence Levels of fun3 RNA Binding of proteins - - - Protein A binds to the promoter region Protein C binds upstream of the promoter + - - Protein A binds to the promoter region - + +++ Protein B binds to the promoter region Protein C binds upstream of the promoter + + + Protein B binds to the promoter region Questions: 1. Please propose a mechanism to explain the above results. You should focus on the question “How does the expression of fun3 gene is tightly regulated so that it is only highly expressed when the rare sugar is the only carbon source”. You must answer what proteins A, B and C are. (8 points) 2. How is protein A regulated? (2 points) (1) glucose turns the repressor on (2) glucose turns the repressor off (3) the rare sugar turns the repressor on (4) the rare sugar turns the repressor off 3. How is protein C regulated? (2 points) (1) glucose turns the activator on (2) glucose turns the activator off (3) the rare sugar turns the activator on (4) the rare sugar turns the activator off 4. How could you make the bacteria always use the rare sugar as the energy source even in the presence of glucose? (8 points)
