PAG 10.1 – Investigating DNA structure using RasMol
The green and blue strands show that DNA
is made of two strands of polynucleotide
chains which are long chains of nucleotides
bonded together by phosphodiester
bonds, with hydrogen bonds between the
nitrogenous bases, a purine always pairs
with a pyrimidine, giving equal-sized
‘rungs’ on the DNA ladder. These can then
twist, into the double helix. This gives the
molecule stability.
The red strands highlight the sugar phosphate backbone
which run antiparallel to each other in opposite directions
from 5’ (where the phosphate group is attached to the fifth
carbon atom of the deoxyribose sugar) to 3’ (where the
phosphate group is attached to the third carbon atom of
the deoxyribose sugar). The five carbon sugar which is
deoxyribose from one nucleotide is bonded to a phosphate
group on another nucleotide by phosphodiester bonds and
the nitrogenous bases are bonded to the sugar molecule.
The molecule is very stable, and the integrity of the coded
Thymine or Adenine. information within the baseAdenine or Thymine.
sequences Adenine
is protected.
This base can be either always pairs with thymine, by
nitrogenous base means of two hydrogen bonds.
because the bases are Adenine is a purine which
complementary to means it has two rings.
each other. Thymine is a pyrimidine which
means it has one ring.
Cytosine or Guanine.
This can be either Guanine always pairs
nitrogenous base with cytosine, by means
of three hydrogen
The green and blue strands show that DNA
is made of two strands of polynucleotide
chains which are long chains of nucleotides
bonded together by phosphodiester
bonds, with hydrogen bonds between the
nitrogenous bases, a purine always pairs
with a pyrimidine, giving equal-sized
‘rungs’ on the DNA ladder. These can then
twist, into the double helix. This gives the
molecule stability.
The red strands highlight the sugar phosphate backbone
which run antiparallel to each other in opposite directions
from 5’ (where the phosphate group is attached to the fifth
carbon atom of the deoxyribose sugar) to 3’ (where the
phosphate group is attached to the third carbon atom of
the deoxyribose sugar). The five carbon sugar which is
deoxyribose from one nucleotide is bonded to a phosphate
group on another nucleotide by phosphodiester bonds and
the nitrogenous bases are bonded to the sugar molecule.
The molecule is very stable, and the integrity of the coded
Thymine or Adenine. information within the baseAdenine or Thymine.
sequences Adenine
is protected.
This base can be either always pairs with thymine, by
nitrogenous base means of two hydrogen bonds.
because the bases are Adenine is a purine which
complementary to means it has two rings.
each other. Thymine is a pyrimidine which
means it has one ring.
Cytosine or Guanine.
This can be either Guanine always pairs
nitrogenous base with cytosine, by means
of three hydrogen
