So if a given DNA molecule contains more guanine cytosine pairs, that means the bonding between our two single stranded DNA molecules is stronger. Now, one other important thing that we have to mention about the double helix is the directionality of our single stranded DNA. So let's take a look at this single stranded DNA that only consists of two nucleotides. So we have the guanine and the anine. Notice that the guanine begins on our five carbon and it goes down to our three carbon, while the second single stranded DNA begins with the third carbon and goes down to the fifth carbon. And this type of opposite or reverse arrangement is known as antiparallel.