what type of chemical bond connects the complementary strands of a dna molecule to each other?
These combinations (A/T) and (G/C) are called base pairs. The two DNA strands are held together by interchain hydrogen bonds. H-bonds pair the bases in one chain to the complementary bases in the other chain. (A/T and G/C). slide 2 of 4. Hydrogen Bonds in DNA A number factors are responsible for the stability of the DNA double helix structure, among them hydrogen bonds. Internal and external hydrogen bonds stabilize the DNA molecule. The two strands of DNA stay together by H bonds that occur between complementary nucleotide base pairs. Two hydrogen bonds occur between the adenosine and the thymine base pairs, and between the cytosine and the guanine there are three. While each hydrogen bond is extremely weak (compared to a covalent bond for example), the millions of H-bonds together represent an extremely strong force that keeps the two DNA strands together. In addition, other groups of the base rings (polar groups) can form external hydrogen bonds with surrounding water that give the molecule extra stability.