MBG 3350 Term Test 1 Questions With Complete Solutions
Ampicillin Correct Answers - inhibits cell wall synthesis
- B-lactamase inactivates drug
Annealing temperature Correct Answers 3-5 C below lowest
primer melting temperature
Chloramphenicol Correct Answers - inhibits protein synthesis
- acetyl transferase inactivates drug
Cleavage close to ends of fragment Correct Answers - cannot
cut vector with two different enzymes in sites too close
- site must be in middle beyond terminal ends
Cloning plasmids Correct Answers propagate certain DNA
fragments
Cloning vector features Correct Answers 1. ability to replicate
in host cells - ORI
2. genetic marker to select for host cells
3. restriction enzyme sites for insertion
Compatible cohesive ends Correct Answers two different
enzymes leave compatible sticky ends that can be ligated
together
- create a hybrid molecule
Cut and paste method Correct Answers using restriction
enzymes and DNA ligases
- cleavage with restriction nuclease
, - covalent linkage by DNA ligase
dam- / dcm- E. coli K12 strains Correct Answers - gene
products methylates sequences preventing recognition by
specific enzymes
- dam: N6 position of adenine
- dcm: C5 position of cytosine
Different plasmid conformations Correct Answers Supercoiled,
linearized and nicked/circular
- supercoiled goes fastest and travels farthest as it is smaller and
less surface area to cause friction
DNA cloning general components Correct Answers 1. plasmid
DNA cloning vectors
2. enzymes to cut, modify and ligate DNA
3. E.coli strains to propagate plasmid DNA
4. bacterial DNA transformation methods
DNA examination by gel elctrophoresis Correct Answers 1.
agarose is highly purified form of agar that is readily soluble in
polar solvents
2. agarose melted in buffered solution at high temp and
solidifies into porous gel
3. DNA is negatively charged an migrates toward positive
electrode
4. migration inversely proportional to log of size
5. DNA is stained by dye/chemicals to be observed
Ampicillin Correct Answers - inhibits cell wall synthesis
- B-lactamase inactivates drug
Annealing temperature Correct Answers 3-5 C below lowest
primer melting temperature
Chloramphenicol Correct Answers - inhibits protein synthesis
- acetyl transferase inactivates drug
Cleavage close to ends of fragment Correct Answers - cannot
cut vector with two different enzymes in sites too close
- site must be in middle beyond terminal ends
Cloning plasmids Correct Answers propagate certain DNA
fragments
Cloning vector features Correct Answers 1. ability to replicate
in host cells - ORI
2. genetic marker to select for host cells
3. restriction enzyme sites for insertion
Compatible cohesive ends Correct Answers two different
enzymes leave compatible sticky ends that can be ligated
together
- create a hybrid molecule
Cut and paste method Correct Answers using restriction
enzymes and DNA ligases
- cleavage with restriction nuclease
, - covalent linkage by DNA ligase
dam- / dcm- E. coli K12 strains Correct Answers - gene
products methylates sequences preventing recognition by
specific enzymes
- dam: N6 position of adenine
- dcm: C5 position of cytosine
Different plasmid conformations Correct Answers Supercoiled,
linearized and nicked/circular
- supercoiled goes fastest and travels farthest as it is smaller and
less surface area to cause friction
DNA cloning general components Correct Answers 1. plasmid
DNA cloning vectors
2. enzymes to cut, modify and ligate DNA
3. E.coli strains to propagate plasmid DNA
4. bacterial DNA transformation methods
DNA examination by gel elctrophoresis Correct Answers 1.
agarose is highly purified form of agar that is readily soluble in
polar solvents
2. agarose melted in buffered solution at high temp and
solidifies into porous gel
3. DNA is negatively charged an migrates toward positive
electrode
4. migration inversely proportional to log of size
5. DNA is stained by dye/chemicals to be observed
