BIOL-1362-CH-17-20-Q_36719 - 1 CH 17‐20 (Sadava Text CH...

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Unformatted text preview: 1 CH 17‐20 (Sadava Text CH 12‐14, 16, 17, 19): Questions to Think About CH 17: From Gene To Protein 1. What is meant by “gene expression”? What was the significance of the experiment performed by Beadle & Tatum? 2. Explain the Central Dogma of biology. What is transcription and translation? What are the three RNA components involved in this process and which one(s) is/are associated with transcription and with translation? What are the basic differences between DNA & RNA? 3. What is transcribed in DNA, and how (& with what) is this carried out? Where is transcription initiated? In what direction does RNA synthesis proceed? What is the 5’, 3’ orientation of the transcript relative to the DNA template? 4. How is transcription of a gene initiated in a eukaryote? How is information organized in a eukaryotic gene? Why must eukaryotic transcripts be processed before translation can occur? Describe the RNA processing steps of eukaryotic transcripts (mRNA’s) in order to produce a transcript that is translatable. What features characterize pre‐mRNA? What features characterize mature mRNA? a. What occurs during splicing of mRNA? What components are involved in carrying out this process? 5. What is translated? How are transfer RNA molecules and ribosomes involved in this process? What are the features and the specific functions of tRNA’s and ribosomes? 6. What is the Genetic Code & what are its features? What are the steps involved in deciphering a transcript? In what direction is the transcript “read”? 7. In terms of where the processes occur, how does transcription & translation differ between eukaryotes & prokaryotes? What is polyribosome formation & what cell type carries this out? 8. Once synthesized, are proteins fully functional? If not, what may be required to make it functional? Where are secretory proteins synthesized in a eukaryote and how does this happen? 9. What is a mutation? What is the difference between a somatic and germ line mutation? What is a point mutation? How does a frameshift mutation differ from a nonsense mutation or missense mutation? Distinguish between each of these mutations. What is a silent mutation? How does this occur? CH 18: Control of Gene Expression 10. Why is it necessary for an organism to regulate expression of its genes? What factors influence gene expression? 11. Draw a diagram showing the basic gene structure of a prokaryote. Describe the function of, and label operon, promoter, operator, structural genes, regulatory gene, repressor (regulatory protein). How is transcription prevented? What is an active repressor? an inactive repressor? 12. What is an inducible operon? What is an inducer? When and how are genes of inducible operons expressed? What do the genes in the lactose operon code for? Describe the mechanism of the lactose operon. Under what conditions, and how, does expression of the lac operon occur? When & how is it turned off? 2 13. What is a repressible operon? What is a co‐repressor? When and how are genes of repressible operons expressed? What do the genes in the trp operon code for? Describe the mechanism of the tryptophan operon. Under what conditions, and how, does expression of the trp operon occur? When & how is it turned off? 14. What are some of the features of eukaryotic genomes? What are the levels of eukaryotic gene regulation and briefly describe what each represents? What is “differential gene expression”? 15. What is meant by “regulation of chromatin structure” and why is this important? What occurs to change the chromatin structure? What is the purpose of this? What is DNA methylation and what is the consequence of this? What is genomic imprinting? 16. Draw a diagram showing the features the gene structure of a eukaryote. Label: exon, intron, promoter, enhancers, proximal control elements. Which are the regulatory sequences? How does this gene structure differ from a prokaryote? What are exons & introns? 17. Review the RNA processing steps of eukaryotic transcripts (mRNA’s) from #4 above. 18. Describe the process of eukaryotic gene transcription. What is required to achieve a low, basal level of transcription of a eukaryotic gene? What happens in order to maximize the rate of transcription (what are the components and sequences involved)? How can transcription be stopped or blocked? What is combinatorial regulation of transcription? What is the basis for this? 19. What is meant by co‐ordinated transcriptional control? How does this occur? (use steroid hormone action as the model) Why would this be important? 20. What defines a post‐transcriptional regulation mechanism? Briefly describe the types of these mechanisms. a. What is alternative splicing? What is the result of this? What does this mean in terms of the # genes a eukaryote possesses vs. the # of proteins that eukaryote can synthesize? 21. What defines a translational regulation mechanism? Briefly describe the types of these mechanisms. 22. What defines a post‐translational regulation mechanism? What are examples of this? 23. What is RNA interference, what are miRNA’s and siRNA’s and what happens as a result of this process? 24. What are cancerous cells? What distinguishes them from normal cells? What is a tumor and how are benign tumors distinguished from malignant tumors? What is metastasis? 25. What are proto‐oncogenes and how can these transform into oncogenes? What are tumor suppressor genes and what is their role in a normal cell? What are the functions of tumor suppressor gene TP53? 26. What are the common features of cancerous cells? In general, how does cancer progress? How do viruses play a role in some cancers? 27. Are all cancers hereditary? Why or why not? Does inheritance of a cancer causing allele mean an individual will come down with cancer? Why or why not? 3 CH 19: Viruses 28. How are viruses defined? What are the general features of a virus? What are the similarities & differences between a bacterial virus and an animal virus? 29. What is meant by viral infectivity? Can a virus infect any cell? Why or why not? What does host range of a virus mean? How could an emerging infectious disease occur? 30. What is a phage and what is the lytic cycle and what are the stages of such a cycle? Briefly describe each stage. What occurs during the lysogenic cycle of the lambda (λ) phage? Describe the steps of this cycle. In the lambda phage, how are the lytic and lysogenic cycle integrated, i.e., when it would go from one cycle to the other? 31. Describe the basic mechanism of a lytic infection by an animal virus such as the influenza virus. Does this differ in any way from a bacteriophage infection? (Hint: compare the entry of both types into their respective host cell) 32. There are different types of RNA viruses. Among such viruses, what different roles can the RNA genome have in different viruses? 33. What are retroviruses? How does a retrovirus copy its genetic material? What is the flow of information in a retrovirus, i.e., is it DNA RNA protein? How do they infect cells and what are the possible outcomes of such an infection? 34. Define and describe viroids and prions. How do prions “replicate”? CH 20: Biotechnology 35. What is recombinant DNA? What does it mean to “clone a gene”? How does recombinant DNA technology relate to biotechnology (what is biotechnology?) 36. What is the function of the following “tools” used to produce recombinant DNA molecules? a. b. c. d. Restriction enzymes Vector DNA ligase Host cells What do you start with, and what is the first step in preparing recombinant DNA molecules? 37. How do restriction enzymes work? What are palindromic sequences? What are “sticky ends”? How many fragments would be generated from this DNA sequence using EcoRI (recognizes G*AATTC C TT AA*G)? 5’ A A T C T T A A G G G C G A A T T C C C T 3’ 3’ T T A G A A T T C C C G C T T A A G G G A 5’ 38. What is the purpose of a cloning vector? What are the basic features of a plasmid vector? What is meant by “selectable marker”? 39. What is the basic idea behind the two‐report gene strategy for cloning a gene as discussed in class, specifically using a cloning vector (plasmid) that has an antibiotic resistance gene and the lacZ gene? Why do 4 you have to cut DNA molecules that are to be used for recombinant DNA formation with the same restriction enzyme? What is the purpose of transforming host cells with recombinant DNA? What is meant by recombinant plasmid vs. nonrecombinant plasmid? 40. Do the “Recombinant DNA” practice exercise in the VNET UNIT 2 folder titled “Practice Problems & Exercises” and answer the questions provided in here. 41. What is gel electrophoresis, how does it work, and what is it used for? 42. What is a gene library and what does it represent? Of what use is a gene library? 43. What is an expression vector? For what purpose would one use such a vector? What is the important feature is has that allows it to act as an expression vector? 44. What is a cDNA library? What does is represent? Is it the same as a gene library? How do you prepare a cDNA library (what enzyme do you need?) What is a DNA microarray and how are cDNA libraries used in conjunction with these? 45. What is PCR? What components are needed to carry out PCR? What is the end product of a PCR reaction? What applications does PCR have? 46. What is the purpose of performing a Southern blot? How is this done? 47. What is the purpose of gene therapy and how is it performed? What kind of vectors, and of what type, are used for this procedure? 48. How does one clone an animal? What is the technique of nuclear transplantation? Why is the procedure so inefficient? In an animal cloning experiment, who is the “offspring” a clone of? 49. What is therapeutic cloning? How does this differ from the cloning procedure in #34? What is the same? What are stem cells? How do these apply to therapeutic cloning? 50. What are genetic profiles? How does one generate such a profile? What kinds of DNA sequences are examined in this process? What applications does this technique have a role in? ...
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This note was uploaded on 04/23/2010 for the course BIOL 1361 taught by Professor Knapp during the Spring '05 term at University of Houston.

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