gel electrophoresis and genetics Flashcards
gel electrophoresis
a technique used to separate DNA, RNA, and proteins for analytical purposes
how does the electrophoresis procedure separate pieces of DNA
it separates DNA by molecular size and shape so they can be viewed and identified
in gel electrophoresis what way does the DNA travel towards
when an agarose gel is added, the negatively charged DNA moves toward the positive electrode.
do all size of DNA move at the same rate?
no, different sizes of DNA will move at different rates
when does gel electrophoresis stop?
gel electrophoresis stops when the dye has moved 2 cm above the bottom of the gel.
what light is the gel viewed under
UV or white light
what is the role of light in the process
the light allows one to see the DNA fragments and how far apart they are from each other
what is agarose made up of?
agarose is made up of sugars that form crosslinks which form pores in the gel matrix
what do the pores in agarose do?
they allow for separation of substances by size
what is PCR(polymerase chain reaction)
PCR make multiple copies of a particular segment of DNA
what can PCR help us do?
PCR allows us to look at one region of DNA that can be cut into smaller fragments so that they are easily visible upon separation
Whats a restriction enzyme?
a restriction enzyme is used to cut the DNA into smaller pieces after the DNA has been copied many times
how do restriction enzymes work?
they scan the DNA molecule and cut at specific regions, forming fragments of DNA of different sizes.
what do point mutations do in restriction sites?
they can render them unable to be recognized by these enzymes
what do substituitions do to restriction sites
they can alter the restriction site which allows for identification of individuals based on fragment sizes generated by cutting DNA with these enzymes
why is PCR important?
it makes many copies of the DNA and it selectively amplifies only parts of the genome
taq polymerase
its withstands the rigors of extreme temperature changes that have to occur for DNA to be copied the vast number of times require to amplify a tiny amount of DNA into an amount that can be seen
what charge do DNA molecules have?
DNA molecules are negatively charged due to the negative phosphate structure
do all DNA molecules respond to the electric field the same?
no different sized DNA molecules will respond differently to the electric field because it has a different number of phosphate groups. Smaller pieces of DNA will move faster than larger ones
charge of agarose
neutral
steps of gel electrophoresis
extraction
PCR
enzymatic digest
Gel electrophoresis
chromosome
long strand of DNA
gene
a piece of DNA that codes for a specific trait
homologues
matching chromosomes in a pair
