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Test your basic knowledge |

Molecular Biotechnology 2

Subject : engineering
Instructions:
  • Answer 50 questions in 15 minutes.
  • If you are not ready to take this test, you can study here.
  • Match each statement with the correct term.
  • Don't refresh. All questions and answers are randomly picked and ordered every time you load a test.

This is a study tool. The 3 wrong answers for each question are randomly chosen from answers to other questions. So, you might find at times the answers obvious, but you will see it re-enforces your understanding as you take the test each time.
1. Genes that are put into a new host so that the new host can gain new/correct function






2. Primers anneal to complementary sequences on DNA template and determine the boundaries of the amplified product.






3. Four Components: 1. Template (Target DNA) - doesn't need to be purified and can be from anything 2. Primers (short oligonucleotides) 3. dNTP (building blocks) 4. Thermostable polymerase - no need for RNA primers like in actual DNA replication






4. 1. Antibiotic Resistance: gene that degrades toxic compounds 2. Auxotrophic Marker: host is missing some essential amino acid/nucleotide and cell needs it to grow (eg. uracil) - nutritional markers






5. Cell lysis --> new phages. In nonrestrictive bacteria - there is more chance lysis. Plaques appear where cells have lysed.






6. SDS lysis cells - potassium acetate/acetic acid is used to neutralize pH and precipitates lipids and large proteins - centrifuge to separate out plasmid DNA from precipitates






7. A host for recombinant DNA because it can grow fast and to a high cell density. It can also transcribe most foreign genes efficiently and there are many strains that facilitate genetic manipulations.






8. Used so the cell isn't killed and can still transfer foreign DNA into a host cell. The DNA can be propagated in a host cell and hosts with the vector can be selected over hosts that don't have the vector. Plasmids - viruses - plasmids + viruses (cosm






9. A DNA Virus that infects bacteria with its chromosomal DNA. The Phage DNA is linear (35-50 kb) but circularizes in host. It encodes virus specific enzymes and is replicated in the host. It gets integrated into bacteria genome.






10. DNA sequencing - Understand biological processes - Study the function of encoded protein - Introduce a mutation into the gene - Evolve a protein towards desirable functions - Obtain large amounts of a protein






11. Increases specificity - sensitivity - and yield without redesigning primers. The initial annealing temperature is above the projected melting temperature of the primers being used. It then transitions to lower - more permissive annealing temperature






12. Need: polymerase - dNTP (one is labeled with 32P to provide signal) - ddNTP (3'H will terminate DNA synthesis; dideoxyribose; only one is put in and added in excess) - synthesizes DNA and can deduce sequence wherever DNA stops synthesizing because o






13. A DNA which is complementary to an RNA (a complementary DNA); Generally made by reverse transcription of mRNA. (1) purification of mRNA with polyT because mRNA has lots of polyA on 3' end - (2) first strand DNA synthesis using RTase - (3) second stra






14. Directional cloning of a DNA fragment - single site cloning - blunt end cloning - polylinker - creating new restriction sites






15. During meiosis - homologous recombination happens in chromosomes to generate offspring diversity. Recombination is used to repair DNA damage and can be induced by a wide array of environmental stresses.






16. 1. Use RTase to go from RNA to DNA 2. Use RNAseH to get rid of RNA 3. Use TaqP to make top strand of DNA - can't detect quantity of RNA/DNA






17. The number of cycles required for the fluorescent signal to pass the threshold (background level). This is inversely proportional to the amount of target nucleic acid.






18. dNTP is added to the reaction Each time dNTP is incorporated to DNA - pyrophosphate (PPi) is released in a quantity equimolar to the amount of incorporated nucleotide.






19. Can be used to linearize circular DNA - can have double digest - usually done at 37C but some done at 55C - digest time depends on the amount of enzyme






20. 4-8 bp long (usually 6). Mostly palindromic because the nuclease is 2 enzymes coming together. There are 3 types of cleavage: (1) blunt ends - (2) 5' overhang sticky end - (3) 3' overhang sticky end.






21. 1. Primer length is between 18-24 nucleotides long. 2. Duplex stability: both primers need to have similar Tm to have the same hybridization kinetics during the template annealing phase. Remove bases to have the same Tm 3. Non - complementary primer






22. Two components to perform the traceless recombination on chromosomes: 1. FLP recognition target (FRT): inverted repeat 2. FLP recombinase






23. From bacteriophage lambda and help in the removal of chromosomal genes in e.coli. As little as 30 nt homologous region is required - which can be introduced as overhangs in a PCR reaction using the selection marker as template 1. Gam - protects line






24. E. coli polymerase denatures at 95C and new enzyme has to be added each time. TaqP is a thermal stable organism and only need to add once - but will denature after 30 min at 95C (may be able to reduce temperature after a few cycles; increase denatura






25. 1. Cycles of temperatures 2. 94C denatures DNA 3. Lower temperature so primers can bind to DNA at specific locations 4. Polymerase carries out templated DNA synthesis with primers at an optimal temperature (~72C) 5. Product serves as the template for






26. As the process continues - the complementary DNA strand is built up and the nucleotide sequence is determined from the signal peaks in the pyrogram.






27. Each clone on the plate has the gene of interest - but there are only a few colonies that have the gene. Once do a filter paper - you need to do it again around the area where colonies popped up first until finally know where the colony is.






28. Type I and III: cut and modify DNA by methylation - binding and cutting sites differ - requires ATP to move along DNA - and not efficient for DNA manipulation Type II: has only restriction activity - no modification; cutting sites are adjacent or wit






29. 1. Delete genetic information on the chromosomes of species of interest (knock outs) 2. Insert new genes and DNA sequences into desired positions on the chromosome (not relying on plasmids) 3. Generate genetically engineered species






30. ATP sulfurylase quantitatively converts PPi to ATP in the presence of APS. This ATP drives the luciferase mediated conversion of luciferin to oxyluciferin that generates visible light in amounts that are porportional to the amount of ATP and is detec






31. 1. Detecting pathogens using genome- specific primer pairs 2. Screening specific genes for unknown mutations 3. Genotyping using known STS (sequence tagged sites) markers






32. 20-25 nt oligonucleotide that will hybridize to DNA of interest. It can be radiolabeled with kinase and 32P-ATP or fluorescently labeled.






33. Restriction nucleases - electrophoresis - vector - ligase - bacterial host - identifying the cloned gene






34. Strong positive reactions with abundant nucleic acid






35. Plasmids have an ori sequence for replication. The sequence of ori and plasmid encoded proteins determine the 'copy- number' of plasmids. Stringent control of replication (1 copy per cell division - low cell copy number plasmid); relaxed control of r






36. The first reverse transcriptase specifically purified for use in first stand cDNA reactions






37. A technique that sequences the N terminus and C terminus sequence of purified proteins. These sequences can be used to design degenerate primers and probe a gene library. (1) Purify protein from cell sample - (2) break it up - (3) enzyme assay - (4)






38. Extrachromosomal - circular DNA that has autonomous - self- replicating genetic elements. Found in bacteria - yeast. Transferred to daughter cells during cell division. Size varies from 1kb ~ 200 -000 kb.






39. Apyrase - a nucleotide degrading enzyme continuously degrades unincorporated dNTPs and excess ATP. When degradation is complete - another dNTP is added.






40. Introduce DNA into bacteria. Transformation efficiency can be increased by making cells competent (treating with cold CaCl2 and heat shock at 42C).






41. Know how much DNA is amplified by using Tagman which has fluorescent dye (SYBR Green) and quencher. Energy is transferred from F to Q when TaqP excises F with 5' to 3' exonuclease activity.






42. Each cell can maintain different plasmids with different selection markers. If the plasmid has the same selection marker - one will be lost. Transformation is very inefficient (<1% of the cell can be transformed).






43. 1. Label one end of DNA with radioactivity 2. Cut DNA at different places wherever A/G/C/T pop up using different chemicals 3. Line up DNA pieces by size using gel electrophoresis.






44. Need primers - dNTP - template - thermostable polymerase - buffer - primer overhangs introduce nonnative sequences - primer mismatches introduce mutations - stops because taqP denatures after awhile






45. Weak reactions with minimal nucleic acid (representing an infection state or environmental contamination).






46. The host's immune system that protects against foreign DNA (DNA binding proteins). It protects the hosts DNA through methylation and digests DNA that isn't methylated. Hydrolyze phosophodiester bond at specific sequences. Binding/cutting sites can be






47. Fluorescent dye is attached to 3' of each of the four bases (ddNTP) and will emit a narrow spectrum of light when struck by an argon ion laser beam. All four ddNTP can be added to the same reaction. >800 bases can be sequenced






48. Introduced on plasmids sensitive to temperature






49. Used to remove selection marker after Red- mediated recombination.






50. 1. If a product is formed: PCR can be unsuccessful if the quality of DNA is poor - one of the primers doesn't fit - too much starting template (non - specific binding) - optimization 2. Product is of the right size: primers may bind to different part






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