Chemicals that modify nucleobases – example: alkylating agents
Base analogs - like AZT
Intercalating agents – like ethidium bromide
The three classes of chemical mutagens
UV light is a thymidine dimmer and X-rays nick
the DNA backbone.
The two best examples of radiation damage of DNA (X-rays, UV) and what it type of damage they do
The sequence of nucleotides in the DNA of an
The properties of a cell determined by the
expression of the genotype
A change in the nucleotide sequence of a cells DNA that is then passed on to daughter cells.
Transmission of DNA from one bacterium to
another through conjugation, DNA-mediated transformation, or transduction
Horizontal gene transfer
Transfer of a pathogen from one person to
another through contact, ingestion of food or water, or via a living agent such as an insect
Organisms that use light as a form of energy
A microorganism that requires an organic growth factor
Describes an organism that has the typical characteristics of the species isolated from nature
A mutation in which the wrong nucleotide has
Mutation in which only a single base pair is
Mutation resulting from the addition or deletion of a number of nucleotides not divisible by three.
Frame shift mutation
the addition of nucleotides causing an mutation or frame shift
Movement of a piece of DNA from one DNA site to another in the same cell.
Using the energy of light to break the covalent
bonds joining thymine dimmers, thereby restoring the DNA to its original state
Mechanism of DNA repair in which a fragment of single stranded DNA that contains a fragment of single-stranded DNA that contains mismatched bases is removed and replaced.
Technique of selecting mutants by plating
organisms on a medium on which the desired mutants but not the parent will grow.
In microbial genetics, a technique for isolating mutants and identifying organisms unable to grow on medium on which the parents do grow
Technique for the simultaneous transfer of
organisms in separated colonies from one medium to another
A test that screens for potential carcinogens by measuring the ability of a substance to increase the mutation frequency in a bacterial strain
A mechanism of horizontal gene transfer in which “naked” DNA is transferred
Mechanism of horizontal gene transfer in which bacterial DNA is transferred inside a phage.
In bacteria, a mechanism of horizontal gene transfer that involves cell- to- cell contact.
Piece of DNA that is capable of replicating; contains an origin of replication.
A horizontal gene transfer, physiological
condition in which a bacterial cell is capable of taking up DNA
What kind of bond does UV light form between adjacent thymine bases? Why might that be a problem for DNA replication?
UV light causes covalent bonds to form between adjacent thymine molecules on the same strand of DNA,distorting the shape of the DNA (bonds the two T’s together)
The three major types of DNA repair.
DNA polymerase proofreading and mismatch repair;Damaged nucleobase replacement; and Repair of thymidine dimmers
The three types of horizontal gene transfer
Transformation, transduction and conjugation.
Conjugation involves what type of DNA?
In bacteria, a mechanism of horizontal gene transfer that involves cell-to-cell transfer
Transduction involves what type of DNA and uses what vector?
Mechanism of horizontal gene transfer in which bacterial DNA is transferred
Deliberately altering an organism’s genetic information using an in vitro technique.
A type of enzyme
that recognizes a specific nucleotide sequence and then cuts the DNA within or
near that site. (may produce “sticky”
Enzyme that forms covalent bonds between
adjacent fragments of DNA
A technique that uses a electric current to separate either DNA fragments or proteins according to size by drawing them through a slab of gel.
A procedure in which a fragment of DNA is
inserted into a vector and then transferred to another cell, where it then replicates.
Complimentary DNA (encodes the same protein as the original DNA by lacks introns)
DNA molecule, often a plasmid, that functions as a carrier of cloned DNA.
Contains the recognition sequence of several different restriction enzymes.
Multiple cloning site
DNA molecule created by combining DNA from two or more sources
Green Fluorescence Protein
Each cell contains one fragment of a given
Distinct region of a DNA molecule at which replication is initiated.
Origin of replication
Gene that encodes a selectable phenotype such as antibiotic resistance
Used to differentiate cells containing recombinant plasmids from those that contain an intact vector (like the lacZ Gene)
Secondary (insertion) marker
small, machine synthesized piece of DNA used to find specific places on any piece of DNA.
PCR – Polymerase Chain Reactin – method used to create millions of copies of a given region of DNA in only a matter of hours.
a. Denaturation – Heating to 95°C denatures DNA
b. Annealing – Cooling to 50°C allows the added primers to anneal to the single stranded templates.
- c. Extension – DNA synthesis occurs when the temperature is raised to 72°C.
Nucleotide that lacks the 3’OH group, the
portion required for the addition of subsequent nucleotides during DNA synthesis
A piece of DNA, labeled in some manner, that can hybridize to a certain nucleotide sequence as a means to detect that sequence
Fluorescent in situ hybridization – A procedure that uses a fluorescently labeled probe to detect specific nucleotide sequences within intact cells attached to a microscope
A solid support that contains a fixed pattern of numerous different single stranded nucleic acid fragments of know sequences.
Why would one place a gene of interest in a high copy number vector?
This could be done to highly express a gene (like making lots of insulin), or to make lots of the DNA for DNA vaccinations.
What is the most common vector for cloning or other DNA techniques?