Week 1 basic techniques in molecular biology Flashcards
How are double stranded dna molecules held together?
by hydrogen bonding
what do each of the single strands have?
directionality
the two dna strands are…
…antiparallel
What can dsDNA molecules be separated into?
two strands
How are dsDNA molecules separated into two strands?
heating
How are the two DNA strands reannealed?
by cooling
annealing is…
…base specific
what is meant by annealing is base specific?
strands find their complementary sequence on reannealing
How are dsDNA molecules cut?
with restriction endonucleases
What do restriction endonucleases recognise?
specific sequences (to cut the dna)
many bacterial cells have …
…plasmids
what can plasmids of bacterial cells provide?
genetic material to confer resistance / benefit to the cell.
what is dna a polymer of ?
nucleotides.
what can plasmids be used in?
molecular genetics and cloning
What are restriction endonucleases used to do?
used to insert DNA into plasmids
what does dna, a polymer of nucleotides, consist of?
adenine, thymine, cytosine, and guanidine.
what bonds are weaker, hydrogen or covalent?
the hydrogen bonds are weaker
where are hydrogen bonds in dna?
between the base pairs holding the two nucleotide chains / strands of dna together
what kind of backbone does dna have?
sugar - phosphate backbone
DNA molecules are ….
… double stranded
the two strands of dna pair together by…
…complementary sequences forming the pairs
why is dna referred to as a polymer?
meaning it consists of repeated subunits – molecules – in this case
nucleotides.
the DNA polymer chain is formed
by …
…the sugar part of one nucleotide being covalently bonded to the phosphate group of the next nucleotide (phosphodiester bond) – and so on.
in double stranded DNA A always pairs with…
…T