KA1: the structure of dna Flashcards
how many chains of nucleotides make up the dna molecule?
2
what is a nucleotide comprised of?
phosphate, deoxyribose sugar and a base
nucleotides are joined together by ….bond, forming …..
sugar phosphate, forming sugar phosphate backbone
how are the base pairs held together?
by hydrogen bonds
what forms the genetic code?
the base sequence of dna
what is the base pairing rule?
adenine-thymine cytosine-guanine
why is the double stranded structure described as anti-parallel?
one side from 3 to 5 (deoxyribose sugar) opposite side runs from 5 to 3 (phosphate)
how is dna organised in prokaryotes and eukaryotes? brief
P: single circular chromosome and smaller circular plasmids
E: linear chromosomes in the nucleus
explain thoroughly how dna is organised in eukaryotes.
they all have linear chromosomes in the nucleus, which are tightly coiled and packaged with associated proteins called histones.
what cell types are eukaryotes and prokaryotes?
eukaryotes are animal, plant and yeast.
prokaryotes are bacteria.
eukaryotic cells also contain _______ chromosomes in their ________ and ________.
circular
chloroplasts and mitochondria
where is eukaryotic dna found?
in the nucleus
explain why yeast cells are deemed ‘special’.
since they are a type of eukaryote but contain plasmids which are usually only found in prokaryotes
