DNA Flashcards
DNA markers?
specific DNA sequences that can be used to identify individual people or characterize human populations, or to identify and study non-human species
DNA in criminal cases?
DNA left behind can imply the presence of a specific person at that crime scene
What is DNA useful for?
parentage, tracking in migrations of people, ancestry, and disease susceptibility
What are the monomers for DNA?
nucleotides
What are nucleotides composed of?
one or more phosophate grous, a sugar, and a nitregenous base
What are the 4 DNA nucleotides?
adenine (purine)
guanine (purine)
cytosine (pyrimindines)
thymine (pyramindine)
polynucleotide strand? features?
how nucleotides are hooked together
sugar-phosophate backbone, with 5’ end and a 3’ end
nitrogenous base sequence
what are the complementary base pairings
adenine-thymine
cytosine-guanine
Why in a helical shape?
most stable (lowest energy) conformation
What bonds hold DNA together?
hydrogen bonds
What causes DNA denaturation?
heat- breaks the bonds
polyelectrolyte theory?
negative charges on the backbone are spread out to allow for easier access for machinery to read and copy base sequences
DNA polymerization reactions
the process in which DNA molecules can be copied. Catalyzed by enzymes
Why semiconservative in coping DNA?
only have of the orginal strand is kept, the other half is synthesized
DNA polymerase
enzyme responsible for DNA replication
Source of mutation?
errors in DNA replication
In order to replicate DNA, what do you need?
DNA polymerase, free nucleotides and DNA template
ethidium bromide
a fluorescent molecule that is flat and can slide between the stacked base pairs of DNA
how can you visualize DNA with ethidium bromide?
if ultraviolet light is shown on the DNA-ethidium compex, the ethidium bromide absorbs the light and re-emits some of the energy as green light
Agrose
a carb from seaweed that is used to make a jelly with tiny holes
how is agrose used with DNA
determines sizes of DNA when in contact with electrical current and the negatve DNA will migrate down toward the cathode
whats that process called?
electrophoresis
PCR
polymerase chain reaction. used to amplify DNA
What do you need for PCR?
DNA template, DNA primer, free nucleotides, taq polymerase, a thermal cycler