unit 1 key area 1 Flashcards
(16 cards)
how many strands does DNA have
two which form a twisted structure called a double helix
what is a strand of DNA made up of
repeating units called nucleotides
what is a nucleotide made up of
deoxyribose sugar, a base and a phosphate group
how can the two strands in DNA be described
antiparallel
what does the antiparallel structure mean
phosphate group at 5’ end and deoxyribose sugar at the 3’ end
how are nucleotides held together
strong chemical bonds
where do these strong chemical bonds occur
between phosphate of one group and sugar of another
what does the strong chemical bond create
a sugar phosphate backbone
what is the complimentary base pairing rule
adenine - thymine
cytosine - guanine
how are the bases held together
weak hydrogen bonds
where is DNA found in eukaryotes (animal)
nucleus in linear chromosomes,
mitochondria in circular chromosomes
where is DNA found in eukaryotes (plant)
nucleus in linear chromosomes, mitochondria and chloroplasts in circular chromosomes
where is DNA found in eukaryotes (yeast)
nucleus in linear chromosomes, mitochondria in circular chromosomes, cytoplasm in plasmids
where is DNA found in prokaryotes
cytoplasm in circular chromosomes and plasmids
how is DNA packaged
tightly wound around associated histones and packaged into chromosomes
what is a yeast cell
special example of a eukaryote as it has plasmids
