Page 79 - Miracles Within the Molecule

Nitrogen bases
pro duce hydro gen
bonds that join the
DNA arms. T pairs
form two bonds
with A pairs, and G
pairs form three
bonds with C
pairs.

Due to its hydro gen bonds, the
DNA helix is excep tion al ly reg -
u lar, and the DNA mol e cule
makes very reg u lar turns. The
cova lent ester bonds in the
back bone give this mol e cule a
strong struc ture and pre vent its
break ing or stretch ing, even
though it is tight ly fold ed in the
cell nucle us. Through these
two dif fer ent bonds, DNA is
suf fi cient ly mobile and strong
to per form all its func tions.

77