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Molecular Biotechnology

Subject : engineering
Instructions:
  • Answer 50 questions in 15 minutes.
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  • Match each statement with the correct term.
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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. Eukaryotic. mRNA that codes for one protein






2. Structural and functional units of life. All organisms are made of cells - all cells are derived from preexisting cells - the purpose of a microorganism is to make another microorganisms as quickly as possible; alter metabolism of microorganism to ma






3. Important to suppress mutations at 3rd position and you don't need to have a lot of stop codons; cells can be more flexible






4. The process of increasing the expression of inducible genes






5. Operator site; araC bound at this site can simultaneously bind to the araI site to repress transcription from Pbad promoter






6. A unicellular organism that lacks a nucleus and membrane bound organelles






7. 1. Ethidium bromide staining 2. P32 - P33 radioactivity 3. Fluorescence 4. Agarose gel electrophoresis






8. Production of commercial products generated by the metabolic actions of microorganisms.






9. A small catabolite molecule. Its level is determined by the level of glucose in the cell where glucose controls the rate of cAMP formation with ATP. When there is high glucose - there is low levels of cAMP. cAMP activator protein (CAP) has to bind cA






10. A strand segment complementary to the template with a free 3'OH group






11. When arabinose is present - it binds to araC and allosterically induces it to bind to araI instead araO2. If glucose is absent - then the presence of CAP bound to its site between araO1 and araI helps break the DNA loop and helps araC bind to araI






12. Unvarying expression of gene






13. A segment of DNA molecule contains the information required for synthesis of a functional biological product






14. Codes for three enzymes needed to catalyze the metabolism of arabinose. The operon is regulated by araC gene product.






15. A haploid organism that is diploid for a small region of the chromosome (partial diploid)






16. Attenuation






17. The ribosome translating the leader peptide arrives at the two tryptophan codons and has to wait for tryptophan. During this time - RNAP continues to transcribe. Stem loop between 2 and 3.






18. In the presence of glucose and lactose - bacteria grows first on glucose - then growth levels off - and starts growing on lactose. You have diauxie growth because (1) CAP helps recruit RNAP. in the presence of glucose - CAMP is low so it can't bind t






19. A cell that contains a nucleus and membrane bound organelles






20. C - N - O - H make up 99% cell weight - 70% is water






21. Replication > DNA > Transcription > RNA > Translation > Protein






22. Determines amino acid selection. A noncognate amino acid charge incorrectly to the tRNA will be inserted into the protein. Introduce new amino acid by using tRNA for UAG.






23. Select correct ribonucleotides; loss of sigma factor - transcription bubble - no need for primers






24. TrpE through trpA are five enzymes that catalyze the synthesis of the amino acid tryptophan from chorismic acid. If the cell has enough tryptophan - then it doesn't need to waste energy transcribing this mRNA. In the presence of tryptophan - the oper






25. 1. Initiation: unwind DNA at the origin of replication (ori) - bidirectional replications; regulated as required for cell division 2. Elongation: requires RNA primer to replicate 3. Termination: signaled by Ter sequence






26. Gene products decrease in concentration under particular molecular circumstances






27. AARS charges the correct amino acid to tRNA in a two- step reaction.






28. 1. mRNA: encodes genetic information 2. tRNA: transfer RNA - involved in protein synthesis (DNA to amino acids) 3. rRNA: ribosome RNA - involved in protein synthesis (polypeptide formation) 4. Ribozymes and RNAi - Can store genetic information and ca






29. 1. mRNA - template for protein synthesis 2. tRNA - carrier of amino acid (the adaptor)3. aminoacyl- tRNA synthetase - pairs tRNA with the cognate amino acid - needs ATP 4. ribosome - site of protein synthesis - read in three frames - start codon is A






30. The first two bases of the codon always form strong Watson -Crick base- pairing. The first base in the anticodon determines the number of codons a tRNA can recognize. The first position in anticodon is often modified to inosine to facilitate wobble b






31. In prokaryotes - related genes often arrayed in tandem. A unit of bacterial gene expression and regulation - recognized by a regulator gene product






32. Operator site - araC binds to this site and represses its own transcription from the PC promoter. In the presence of arabinose - araC bound at this site helps to activate expression of Pbad promoter






33. 1. Capping: 5' phosphate capped by 7- methyl guanosine and is a 5'-5' linkage instead of 5'-3' This makes RNA more stable 2. Intron removal 3. Export to cytoplasm 4. Polyadenylated mRNA precursor






34. Multiple effects from a single gene






35. The process in which an exact copy of the double strand DNA is made. It is a templated process and occurs from 5' to 3' end. DNAP - RNA primer; semiconservative (each strand is a template for the replication of the complementary strand)






36. Comprised of >50 proteins associated with rRNA units. Site of protein synthesis and binds mRNA and finds protein synthesis initiation sites. It also binds aa- tRNA and catalyzes peptide bond formation.






37. Chromosome (contains host genetic information) - plasmids (prokaryotes; small - self- replicating DNA; supercoil) - free nucleotides






38. In E. coli - DNAP III can unwind DNA (helicase) and replicate both strands of DNA. It also has proofreading activity and corrects mistakes 3' to 5' exonuclease






39. 1. Nucleic acid hybridization: (a) bind single stranded DNA to a membrane support - (b) add single stranded labeled DNA (probe) under appropriate conditions - (c) wash the support to remove excess unbound labeled probe DNA - (d) detect the hybrid seq






40. Genes for products that are required at all times.






41. 1. LacI- makes an internal inducer -- NO. Found that lacI- doesn't dominate over lacI+ and is not always constitutive. 2. LacI- is a repressor protein -- YES. LacI+ dominates over lacI- because when both are together - lac operon is inducible. LacI m






42. 1. Synthesis of commercial products by recombinant organisms 2. Biopolymers 3. Bioremediation 4. Biomass utilization






43. The small ribosomal subunit binds to 5'-G cap on processed mRNA (no RBS) - uses met instead of fmet for initiation; monocistronic translation






44. The repressor dimer (aporepressor) can't bind to the repressor. Transcription from the promoter is not stopped. When tryptophan is bound to the repressor dimer - the repressor changes configuration so that it can bind to the operator and transcriptio






45. Ribosome doesn't stop at trp codons and stem loop forms between 3 and 4. RNAP stops prematurely (attenuated)






46. Operons transcribed as single mRNA and mRNA codes for more than one protein.






47. Polymerase binds to lac promoter weakly by itself and results in low levels of transcription even in the absence of lacI. The activator recruits the polymerase to the promoter region and increases its affinity for the promoter






48. Binds to CAP binding site. In conjunction with araC bound with arabinose - it assists RNAP in binding to the Pbad promoter






49. When arabinose is absent - there is no need to express the structural genes. AraC does this by binding simultaneously to araI and araO2 - making a looped DNA. This blocks access to Pbad promoter. AraC is an autoregulator of its own expression and the






50. Inducer site; araC bound at this site can simultaneously bind to the araO2 site to repress transcription from the Pbad promoter. In the presence of arabinose - araC bound at this site helps to activate expression of Pbad promoter.