Now the reason this binds at the three end is because the DNA polymerase can only form the single strand of DNA. Colin can only elongate that DNA in the five to three direction. And so that primer must form at the five end. So it actually forms at the three end of this DNA molecule so that we have a five M that begins on this side. And likewise the other DNA primer binds until the three end of the complementary DNA molecule so that it forms at the five end. And in the next step, when we add the DNA polymerase, the DNA polymerase can bind onto this section, this section, and can basically elongate that DNA molecule.