And because this contains the adenine nitrogenous base, this nucleotide can be called simply the adenine nucleotide. So we have one nucleotide bonds to a second nucleotide via this phosphodia ester bond. Now, DNA in cells, specifically in human cells, doesn't actually exist as a single strand of DNA. In fact, two strands of DNA that are complementary to one another actually bind to form a double stranded DNA. And that double stranded DNA forms a coil that we call the double helix. And the two single stranded DNAs bond to one another via a special type of dipole dipole bond known as hydrogen bonds.