Study Set Content:
The deoxyribonucleotides are linked together by phosphodiester bonds between the
3'–OH of the sugar
The deoxyribonucleotides are linked together byphosphodiester bonds between the 3'–OHof thesugarof one nucleotide through a
a phosphate moleculetothe5'–OH on the sugar of another nucleotide
The sugar–phosphate linkages formthe (blank) of the polymer to which the variable bases areattached.
backbone
The nucleotide polymer has a free phosphategroupattached to
5'–position of sugar
The sugar–phosphate linkages formthe backboneofthe polymer to which the variable bases areattached.The nucleotide polymer has a free phosphategroupattached to 5'–position of sugar and a free
3'–OH group
The sequence of the polymer is written in the
5’ to3’direction
Secondary structure:
The Double Helix
In the secondary structure of DNA, the twostrandsare
anti-parallel.
That means, the 5’-3’ of one strand is in the(blank) direction to the other strand.
opposite
The bases are stacked in the inside of the
two strands
The bases of one strand pairs with the bases of theother strand of the same plane such that adeninealways pairs with thymine with
two H bonds
Guanine always pairs with cytosine with
3 H bonds
Base pairs in DNA are either
r A-T (adenine-thymine),or G-C (guanine-cytosine).
These A-T and G-C pairs are called
"Watson-Crick"base pairs
These A-T and G-C pairs are called "Watson-Crick"base pairs after the British chemists
James Watson and Francis Crick
These A-T and G-C pairs are called "Watson-Crick"base pairs after the British chemists JamesWatsonand Francis Crick who described the structureofDNA in
1953
These A-T and G-C pairs are called "Watson-Crick" base pairs after the British chemists James Watson and Francis Crick who described the structure in 1953 and subsequently received the
1960Nobel Prize in Medicine
In A-T or G-C, one base is a
purine
while the other is a
pyrimidine
The phosphate group and the sugar units exposethemselves to the
outside of the chain
