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Test your basic knowledge |
Molecular Biotechnology
Start Test
Study First
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. 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
Regulated gene expression
Nonsense suppression
Amino acyl- tRNA synthase
Operon
2. Gene products increase in concentration under particular molecular circumstances
Inducible expression
Ribosomes
Bacterial Transcription
Termination:
3. 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
RNA
DNA Replication
When tryptophan is low
Elongation Factor Tu
4. 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
Cells
Initiation of Translation in Bacteria
DNAP
Elongation
5. 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
Ribosomes
Gene
DNA diagnostic systems
Proteins
6. 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
Bacterial Transcription
Negative regulation
cAMP
Wobble
7. In prokaryotes - related genes often arrayed in tandem. A unit of bacterial gene expression and regulation - recognized by a regulator gene product
Degeneracy
ara operon
araI
Operon
8. 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.
LacI Possibilities
When tryptophan is low
tRNA
Melting temperature (Tm)
9. 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
Gene
Diauxie
araO1
Elongation (Protein)
10. Three sites recruit tRNA and forms peptidyl- tRNA bonds (E - exit; P - peptide; A - acceptor).
Pleiotropic
Monocistronic
Elongation (Protein)
Diauxie
11. Search for site to start transcription - unwind DNA; -35 region and pribnow region (-10 region).
tRNA
Initiation
Degeneracy
Induction
12. The process of decreasing the expression of inducible genes
Repression
Termination:
Activation Lac Operon
Initiation of Translation in Eukaryote
13. 4. Cells + organelle 3. Supermolecular complexes 2. Macromolecules 1. Monomeric units
araO2
TrpR Repression
Levels of Cells
Monocistronic
14. LacY: Transports lactose into the cell LacZ: B- galactosidase LacA: transacetylase LacI: lacI+ cells fully inducible - lacI- were already induced and not responsive to IPTG X- gal: analog of lactose that turns blue when cleaved by lacZ product and o
Lac Operon
Elongation
LacI Possibilities
TrpL
15. A templated process just like in DNA replication and there is no processing steps.
Amino acyl- tRNA synthase
Induction
Termination:
Bacterial Transcription
16. Select correct ribonucleotides; loss of sigma factor - transcription bubble - no need for primers
Elongation
Lac Operon
Eukaryote
Types of DNA
17. Genes for products that are required at all times.
Elongation
Housekeeping genes
Regulated gene expression
TrpL
18. 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.
Regulated gene expression
Constitutive expression
Ribosomes
What makes up a cell?
19. 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
cAMP
Repressible expression
araI
Monocistronic
20. AARS charges the correct amino acid to tRNA in a two- step reaction.
Repression
Amino acyl- tRNA synthase
RNA
ara operon
21. 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
Initiation of Translation in Bacteria
Components of Translation
araO1
Levels of Cells
22. Unvarying expression of gene
Elongation (Protein)
Constitutive expression
araO2
Molecular Biotechnology
23. 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
Negative regulation
Levels of Cells
Trp operon
3 Stages of DNA Replication
24. 1. Synthesis of commercial products by recombinant organisms 2. Biopolymers 3. Bioremediation 4. Biomass utilization
Eukaryote
Impacts of Molecular Biotechnology
Ribosomes
Positive regulation
25. 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.
Induction
araI
Housekeeping genes
Initiation
26. A unicellular organism that lacks a nucleus and membrane bound organelles
TrpR Repression
Initiation of Translation in Bacteria
Prokaryote
Activation Lac Operon
27. A segment of DNA molecule contains the information required for synthesis of a functional biological product
Eukaryote
Bacterial Transcription
Gene
Prokaryote
28. Chromosome (contains host genetic information) - plasmids (prokaryotes; small - self- replicating DNA; supercoil) - free nucleotides
araI
araO1
Types of DNA
Activation Lac Operon
29. Ribosome doesn't stop at trp codons and stem loop forms between 3 and 4. RNAP stops prematurely (attenuated)
Bacterial Transcription
RNA Primer
When tryptophan is high
TrpR Repression
30. Important to suppress mutations at 3rd position and you don't need to have a lot of stop codons; cells can be more flexible
Induction
Degeneracy
Gene
Ribosomes
31. Operator site; araC bound at this site can simultaneously bind to the araI site to repress transcription from Pbad promoter
Bacterial Transcription
Operon
Types of DNA
araO2
32. 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
Nonsense suppression
Induction
3 Stages of DNA Replication
Inducible expression
33. A haploid organism that is diploid for a small region of the chromosome (partial diploid)
cAMP
Merodiploid
Eukaryotic Transcription
Types of DNA
34. Production of commercial products generated by the metabolic actions of microorganisms.
Open reading frame
Visualization of DNA
Molecular Biotechnology
Elongation Factor Tu
35. 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
ara operon
Termination:
LacI Possibilities
Housekeeping genes
36. 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
Constitutive expression
DNAP
Levels of Cells
Activation Lac Operon
37. Functions: enzymes - regulation - structural - cellular functions Polymers of amino acids and connected by peptide bonds. Can fold into complex structures.
ara operon
Proteins
Visualization of DNA
Inducible expression
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
Components of Translation
Gene
Lac Operon
DNAP
39. 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
RNA
TrpR Repression
Bacterial Transcription
araO2
40. A strand segment complementary to the template with a free 3'OH group
Cells
RNA Primer
Activation Lac Operon
ara operon
41. Codes for three enzymes needed to catalyze the metabolism of arabinose. The operon is regulated by araC gene product.
Operon
ara operon
LacI Possibilities
Bacterial Transcription
42. Binds to CAP binding site. In conjunction with araC bound with arabinose - it assists RNAP in binding to the Pbad promoter
Types of DNA
Monocistronic
Constitutive expression
CAP
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
Positive regulation
What makes up a cell?
araO2
Components of Translation
44. 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
mRNA processing
Impacts of Molecular Biotechnology
Initiation
Activation Lac Operon
45. When half DNA strand has been denatured. Determined by GC content (triple bond)
araI
Melting temperature (Tm)
Retrovirus
Degeneracy
46. 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
When tryptophan is high
Components of Translation
Prokaryote
Housekeeping genes
47. Attenuation
Initiation of Translation in Bacteria
Visualization of DNA
TrpL
Proteins
48. A reading frame without termination codon among 50 or more codons. Usually correspond to genes that encode proteins
cAMP
Open reading frame
Negative regulation
Initiation of Translation in Eukaryote
49. 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.
Repression
Elongation (Protein)
When tryptophan is low
LacI Possibilities
50. Reverse Transcriptase
Retrovirus
What makes up a cell?
DNA diagnostic systems
Eukaryotic Transcription