A portion of a DNA template strand has the base sequence
5′-...ACGCGATGCGTGATGTATAGAGCT...-3′
Identify the sequence and polarity of the mRNA transcribed from this fragmentary template-strand sequence.

Question

A portion of a DNA template strand has the base sequence

5′-...ACGCGATGCGTGATGTATAGAGCT...-3′

Identify the sequence and polarity of the mRNA transcribed from this fragmentary template-strand sequence.

Accepted Answer

Hello, everyone and welcome to today's video. So given the following DNA template strand, five prime G T C A G G C T A G A T C G A three prime. What would be the sequence of the M R and E transcribed from the DNA template sequence? As answer choice A we have five prime U C G A U C U A G C C U J ac three prime as answer choice B we have five prime C A G U C CJ A U C U A G C U three prime as answer choice C we have five prime T C G A T C T A G C C T G ac three prime. And as answer choice D, we have five prime C A G T C C G A T C T A G C T. All right. So all we have to do in order to solve this problem is that we're going to copy and paste into the screen, the DNA template strand that we have that were given in the problem in order for us to be able to transcribe it into M R N A. So remember that when this M R N A is transcribed, it is going to happen starting from the three prime. And now we can start simply transcribing the base pairs or the nuclei or, or in the DNA template strand into R N A. So let's do that G is translated or transcribed into C T into AC, into G A, into U because remember that we're dealing with R N E, then we have C C G T is translated in it transcribed into a, A, into U G, into C A, into U T, into AC, into G G, into C and A into U. And then we have five prime at D N here. However, if we look at our answer choices, all of them are going to be five prime to three prime or M R N A strand is going to be three prime to five prime. So we need to flip this in order to have the correct order that we can compare to our answer choices. So let's do just that we're going to take the M R N A strand and basically flip it. So it's going to be U C G A U C U A G C C U G AC and then three prime. Now looking at our answer choices, the correct answer choice here is going to be a, this is the strand that is complementary or is exactly the same as the M R N A strand that we were able to come up with. Now, this is going to be five prime U C G A U C U A G C C U G ac three prime, which is exactly what we have. Now, I really hope this video helped you and I hope to see you on the next one.

A portion of a DNA template strand has the base sequence
5′-...ACGCGATGCGTGATGTATAGAGCT...-3′
Identify the sequence and polarity of the mRNA transcribed from this fragmentary template-strand sequence.

Verified video answer for a similar problem:

Key Concepts

Transcription

Polarity of Nucleic Acids

Base Pairing Rules