Genetics - DNA Flashcards
what is a genome
entire set of the genetic material of an organism
what is a gene
section of DNA that codes for a particular sequence of amino acids that form proteins
what is DNA
the genetic material found in the nucleus of a cell
what is the structure of DNA
polymer made up of two strands coiled around to make a double helix
what does a nucleotide consist of
sugar and phosphate group with one of four different bases attached to the sugar
what forms the backbone of the DNA
The phosphate and sugar section of the nucleotides form the ‘backbone’ of the DNA strand
what do each nucleotide have in common
same phosphate and deoxyribose sugar, but differ from each other in the base attached
what are the complimentary base paris
Adenine always pairs with Thymine
Cytosine always pairs with Guanine
how are complimentary base pairs joined
in the double helix together by pairing up by forming weak hydrogen bonds with each other
how can DNA be extracted from fruit
Mash the fruit and mix this into a beaker containing a solution of detergent and salt
Filter the mixture into a test tube
add ethanol to the filtrate
The DNA will appear as a stringy white precipitate
extracted using a glass rod
what is the role of the detergent and the salt
The detergent breaks down the cell membranes causing the fruit cells to release their DNA
the salt causes the DNA to stick together
what is the role of ethanol
This causes the DNA to precipitate as DNA is not soluble in cold alcohol
