DNA Flashcards
(16 cards)
what is DNA?
DNA is genetic material.
where is DNA found?
in the chromosomes in the nuclei of cells.
what is DNA made up of?
DNA is a polymer made of many monomers called nucleotides joined together.
what shape is DNA?
it is a double helix.
what is a gene?
a gene is a short piece of DNA that codes for a specific protein.
what are the two strands of the double helix held together by?
pairs of bases.
what are the four different types of bases called?
A= adenine
T=thymine
C=cytosine
G=guanine
which bases are complementary?
A goes with T
C goes with G
what holds the bases and DNA strands together?
weak hydrogen bonds.
what does each nucleotide consist of?
a sugar, a phosphate group and one base
what is the first step of extracting DNA from fruit?
- Mash the chosen fruit and put it into a beaker containing a solution of detergent and salt.
why do we add the detergent and salt?
the detergent breaks down the cell membrane to release the DNA.
the salt will make the DNA stick together.
what is the second step of extracting DNA from fruit?
filter the mixture to remove and insoluble bits and the extra froth.
what is the third step of extracting DNA from fruit?
slowly add some ice cold ethanol/alcohol to the mixture.
what does the ice cold ethanol/alcohol do?
it precipitates the DNA.
what is the result of the practical?
DNA will start to come out of solution as its not soluble in cold ethanol/alcohol. it will appear white and stringy (a solid) that can be carefully fished out with a glass rod.
