In this video, we're going to do an overview of the entire process of transcription. However, it's important to keep in mind that as we continue to move forward in our course, we're going to continue to break down transcription in more detail. And later in our course, in a separate video, we'll talk about the individual steps of transcription in more detail. And here in this video, we're just doing an overview of the entire process. And so it's important to note that the two strands of DNA in a gene are referred to as either the coding strand or the template strand.
Now, it turns out that during transcription, the RNA molecules that are being built are going to have the same exact sequence as the coding DNA strand, and the template DNA strand is just going to serve as a template for building the RNA. But ultimately, the RNA molecule is going to be carrying the message that's in the coding DNA strand. And so the only difference between the RNA sequence and the coding DNA sequence is going to be the fact that it's going to be replacing all of the T's or thymines with U's or uracils. And recall that this is because RNA has uracils, whereas DNA is going to have thymines. And we'll be able to see an example and application of this down below in our example.
Now, it's also important to note that during transcription, the RNA molecule itself is going to be built from its 5' end to its 3' end, and it's going to be built by pairing free RNA nucleotides that are floating around in the cell on a DNA template. And so we'll be able to see that down below in our image over here on this side. Now, this nucleotide pairing is going to occur via Watson and Crick base pairing, which, recall, we already covered in our previous lesson videos, which basically says that A's or adenines will pair with T's or thymines. Or in the case of DNA base pairing with RNA, A's are going to be base pairing with U's, because remember that in RNA, U's are going to replace the T's. And then, of course, we know that G's are going to base pair with C's.
And so, if we take a look at our image down below, we can better understand the overall overview of transcription. And so this example here wants us to determine the sequence for the template DNA strand and for the mRNA transcript given the following coding strand. And so, when we take a look at this side of the image over here, what you'll notice is we have a DNA molecule. And recall that DNA has 2 strands, and each of these two strands, one of them is going to be the coding strand and the other one's going to be the template strand. In this case, the coding strand is at the top here and the template strand is the one on the bottom.
And so it wants us to determine the template DNA strand sequence along with the mRNA transcript sequence that's down below. And so, what's important to note here is that when we look at the coding sequence, coding strand sequence, it is GGA T C. And we know that through Watson and Crick base pairing that the G's are going to base pair with C's, and so these G's here will base pair with C's on the DNA. So we know that C's are going to go in these positions and that A's are going to base pair with T's in the DNA, and so, we will put T's here, and T's will base pair with A's, and, of course, C's base pair with G's. And so this sequence here is the sequence of the template strand.
Now, of course, the process of transcription represented by this arrow is going to use the DNA to build RNA. And the RNA, as we mentioned up above, is going to have the same sequence as the coding DNA strand with this exception right here, replacing the T's with U's. And so what we can see here is that the coding sequence strand is right here at the top, and RNA is going to have the same sequence as the coding strand. So it is going to be GGA, and then, of course, replacing the T's with U's, as we mentioned here, replacing the T's with U's. And so here, instead of having a T at this position, we're going to have a U.
And then, of course, the C here is going to go right here. And so this will be the sequence of the RNA. Now it turns out that in eukaryotic cells, the RNA that is first made is called a pre-mRNA transcript because it's not fully mature, but we're going to talk more details about that later in our course. Now over here on the right, we're kind of showing you more of a zoom out of the overall process of transcription. And recall that the RNA polymerase enzyme, which is this big pink circle in the background, is the primary enzyme involved with transcription.
And so it will bind to the promoter region on a gene and start to transcribe the gene. And so when it transcribes a gene, it's going to be building the RNA, and the RNA is going to be built from its 5' end to its 3' end, again, by pairing free RNA nucleotides that are floating around in the cell on a DNA template. And so you can see that this RNA is being built from its 5' end over here towards its 3' end over here. And the direction of the RNA polymerase is to the right, so transcription is proceeding to the right. And so what you'll notice is that the DNA is going to unwind, and you can see that there's a coding strand and, again, a template strand.
And the RNA, of course, is going to end up taking the same exact sequence as the coding strand. And again, this bottom one that's down here is going to be the template strand of DNA. Now you'll notice that there is going to be a region here highlighted by this box, which is representing an RNA DNA hybrid region. And so, you can see that these free RNA nucleotides that are floating around in the cell are going to be incorporated into this RNA molecule by the RNA polymerase enzyme. And so this here is representing the overall overview of transcription.
And again, as we move forward in our course, we're going to break down this process of transcription in more detail, looking at it step by step. But for now, this here concludes our overview of transcription, and we'll be able to get some practice applying these concepts as we move forward in our course. So I'll see you all in our next video.