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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. 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)






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






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






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






5. 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






6. 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






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






8. Search for site to start transcription - unwind DNA; -35 region and pribnow region (-10 region).






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






10. Unvarying expression of gene






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






12. 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.






13. 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






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






15. A templated process just like in DNA replication and there is no processing steps.






16. 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






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. 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






19. When half DNA strand has been denatured. Determined by GC content (triple bond)






20. 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






21. 4. Cells + organelle 3. Supermolecular complexes 2. Macromolecules 1. Monomeric units






22. Functions: enzymes - regulation - structural - cellular functions Polymers of amino acids and connected by peptide bonds. Can fold into complex structures.






23. Gene products increase in concentration under particular molecular circumstances






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






25. 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






26. Gene products decrease in concentration under particular molecular circumstances






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






28. Attenuation






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






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






32. Start codon is usually ATG - first amino acid is n - formyl- methionine. It is assisted by initiation factors (IF) and requires ribosomal binding sites (RBS). It is a polycistronic protein translation (operon).






33. Release DNA - rewind DNA - release RNA; stop signals or rho mediated termination (hairpin is a palindromic GC- rich region followed by an AT- rich region; Rho is a termination factor that binds to nascent RNA) RNAP has sigma factor that recognizes pr






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






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






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






37. 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






38. Need to remove introns before changing into mRNA - then take mRNA out of the nucleus. Has 3 RNAP (RNAP I synthesizes rRNA - II synthesizes mRNA - III synthesizes tRNA and small rRNA). Transcription factors are similar to sigma factors.






39. 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






40. 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.






41. EF-Tu GTP binds with an aminoacyl- tRNA and brings it to the ribosome. Once the correct aminoacyl- tRNA is positioned in the ribosome - GTP is hydrolyzed and EF-Tu* GDP dissociates away from the ribosome






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






43. 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






44. A reading frame without termination codon among 50 or more codons. Usually correspond to genes that encode proteins






45. The process of increasing the expression of inducible genes






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






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






48. 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






49. Nonsense mutation in gene that results in truncated protein can be lethal. Sometimes a second mutation arises that counteracts the effects of the mutation. Amber stop codon (UAG/TAG/etc) and amber suppressor tRNA (CUA/etc) can restore protein size an






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