DNA and RNA

what does DNA stand for

deoxyribonucleic acid

what does rna stand for

ribonucleic acid

dna nucleotide structure

nitrogenous base, deoxyribose sugar, phosphate group

rna nucleotide structure

nitrogenous base, ribose sugar, phosphate group

base names in DNA

adenine, thymine, cytosine, guanine

base names in RNA

adenine, uracil, cytosine, guanine

purines

adenine and guanine, double ring structure

pyrimidines

cytosine, thymine, uracil, single ring structure

how are h bonds formed

hydrogen donor and acceptor needed, donor usually a strong electronegative atom covalently bonded to a h atom, acceptor is an electronegative atom of neighbouring molecule or ion with a lone pair

meselson and stahl experiment for dna replication

grew a huge population of e coli on a n-15 growth medium, after centrifugation, the heavy dna appears as a low band, bacteria grown in n-15, transferred to a n-14 growth medium, bacteria allowed to replicate once, band appeared in the middle

semi conservative dna replication

dna helicase breaks h bonds between base pairs, double helix separates and unwinds, exposed polynucleotides attract free floating nucleotides which are activated by atp to form complementary base pairs, dna polymerase forms phosphodiester bonds between nucleotides, each new dna molecule contains one new and one old strand