Genetic Engineering
Name at least three enzymes that can be used as genetic tools.
Helicase
Polymerase
Ligase
Reverse Transcriptase
Restriction Endonuclease
Name the type of process that electrically zaps bacteria to create porous capsules to uptake environmental DNA.
Transformation
Name at least 4 influencing factors of microbial death.
exposure time, type of organism, microbial load, agent’s action, environment, organic matter, agent’s concentration
Name the mechanism of sulfonamides and its bacterial target.
Mechanism - synthetic drugs that block metabolic pathways - specifically folic acid
Target - narrow spectrum agains G- rod bac
This enzyme is responsible for deciphering DNA and adding nucleotides in 5' --> 3' direction, however, it does not require helicase to unwind DNA.
RNA Polymerase
Cloning requires a genetic donor, cloning host, and a vector. State the requirements that make a vector.
ORI- DNA replication
Promoter - transcription
Room for gene insertion
Reporter Gene - allows you to recognize whether or not it worked
Name the enzymes that appear in chronological order for DNA Replication.
Helicase @ ORI site, Primase, DNA Poly III, DNA Poly I, Ligase
Name the settings that autoclave requires for sterilization. (ex. temp/pressure/time)
121C/15 psi/15 min
State the formula for the therapeutic index.
TI = Toxic Dose/Minimum inhibitory concentration (MIC)
Name the differences between RNA and DNA.
RNA - single stranded molecule, uracil instead of thymine, nucleotide contains ribose sugar
State the required components of a polymerase chain reaction (PCR).
Template DNA - use heat to unwind DNA
DNA Poly III
Primers (DNA primers)
Nucleotide mix
Name the length of time it takes for a cell to become 2 cells. State the formula.
Doubling time
Starting bacteria # * 2^(n= generation #)
Describe what quaternary ammonia compounds do. Give an example of a quaternary ammonia compound.
Quaternary ammonia compounds (Quats) act as surfactants that alter membrane permeability of some bacteria and fungi
EX. Laurel sulfate
Name at least 3 drug resistant mechanisms that bacteria can use.
Drug inactivation - B-lactamase/penicillin
Decreased permeability - Pseudomonas decreasing receptor # or altering receptors
Activation of drug pumps - pump out drugs if they enter into microbe
Change in drug binding site - binding site on target (ribosome) is altered so drug has not effect
Use of alternate metabolic pathway - folic acid synthesis
Name the mutation:
DNA level - ATC
mRNA level - UAG
Nonsense point mutation
Compare and contrast the processes of DNA replication in the cell versus in a Polymerase Chain Reaction (PCR).
Similarities: DNA Poly III still replicates in 5’ -->3’ direction, template DNA is still being read,
Cell: Entire chromosome replicated, Helicase unwinds, RNA primers, Ligase and DNA Poly I to seal, Leading/Lagging Strand - Okazaki fragments
PCR: Gene of interest, Heat unwinds, DNA primers, No need for extra enzymes due to being DNA, No leading/lagging strands bc DNA completely unwound
Name the three types of temperature categorizations you can put bacteria in and what are their temperature ranges.
Psychrophile - cold loving (optimal temp below 15C and can grow at 0C)
Mesophile - grow at intermediate temps (20-50C) includes most human pathogens
Thermophile - heat loving, optimal temp greater than 45C
Name two chemical controls that can crosslink and deactivate proteins and DNA.
Aldehydes (glutaraldehyde and formaldehyde) and Gases (ethylene oxide gas)
This antibacterial drug is broad spectrum against G+ and G- bacteria. An example of this drug is Ciprofloxacin. However, due to side effects of seizures and brain damage, there is limited use.
Quinolone - inhibit DNA synthesis, specifically by binding to gyrase
Name the locations that occur in eukaryotes and prokaryotes for transcription and translation.
Transcription: proks - cytoplasm, euks - nucleus
Translation: both proks and euks - ribosomes in cytoplasm
If you were a lab technician hired by the Maury Povich Show for an episode on paternity testing, how could you determine which of 4 possible men was a baby’s biological father?
DNA fingerprinting AKA DNA profiling
Relies on polymorphisms (differences in introns between people) which are passed through family
Introns are not expressed and are spliced before leaving nucleus, buffer for mutations as they protect extrons
Obtain introns by using restriction endonucleases to cut up specific nucleotides at palindromes ( CTAG → CATC)
Use Gel Electrophoresis on digested samples to compare differences
The shorter the nucleotide, the faster and further down they travel
Compare sizes and numbers of fragments to determine how similar the introns are
Draw & label the phases of a growth curve in a closed environment.
Lag Phase (none to little cell growth as cells adjusting to their environment), Exponential Growth Phase (cells dividing at max rate), Stationary Phase (nutrients are depleted, growth rate slows and equals cell death rate), Death Phase (rate of death is faster, build of toxins)
Name two methods that combine to destroy AND remove microbes on the skin.
Degermation - mechanically removes
Antisepsis - chemically destroy/inhibit
Name at lease three ways our society encourages the development of antibiotic resistances.
Overuse of antibiotics (lazy docs overprescribing unnecessarily ex. Antibiotics for virus or broad spec when could be more specific)
Incorrect use of antibiotics - too low of a dose or not finishing prescription → bad bac can survive and thrive)
Livestock overuse of antibiotics - (#1 antibiotic use) -
3rd world countries have counterfeit antibiotics and overuse
Situation 1 - Bobby Joe eats a big bowl of fettuccine alfredo (a pasta with tons of cheeeeeeeese). What does lactose do this situation?
Situation 2 - Billy Joe eats a big fat turkey (tons of tryptophan) all by himself (wow). What does trytophan do in this situation?
Situation 1 - lactose is an inducer that inactivates the repressor so that it cannot bind to operator, therefore RNA Poly can transcribe lactase
Situation 2 - tryptophan is a corepressor that activates the repressor so that it can bind to operator, therefore RNA Poly cannot transcribe more tryptophan