complémentarité

CONT: The base-pairing rule is significant because: I. It explains Chargaff's rules. II. It suggests the general mechanisms for DNA replication. If bases form specific pairs, the information on one strand complements that along the other. III. It dictates the combination of complementary base pairs, but places no restriction on the linear sequence of nucleotides along the length of a DNA strand. The sequence of bases can be highly variable which makes it suitable for coding genetic information. IV. Though hydrogen bonds between paired bases are weak bonds, collectively they stabilize the DNA molecule. Van der Waals forces and hydrophobic interactions between stacked bases also help stabilize DNA.