Write the base sequence and label the 3' and 5' ends of the complementary strand for a segment of DNA with the following base sequences:
b. 5'CCCCTTTT3'

Question

Write the base sequence and label the 3' and 5' ends of the complementary strand for a segment of DNA with the following base sequences:

b. 5'CCCCTTTT3'

Accepted Answer

All right. Hello everyone. So this question is asking us to determine the complementary DNA strand for the following sequence which we'll discuss later on in this video. So in addition, we have four different answer choices labeled A through D proposing different possible complementary strands. So first lets start with the given sequence and notice how the given sequence is written from the five prime end on the left to the three prime end on the right. So the sequence reads as follows, we have GT CG A TC and that's the three prime in on the right side. So first, it's important to recognize that the two structures or excuse me, two strands of DNA are described as anti parallel. This means that they run in opposite directions. So the strength that we are given is running from five prime on the left to three prime on the right, because DNA is anti parallel, the complementary strand should run from three prime on the left to five prime on the right. So three prime to five prime is the correct orientation of our complementary strand given that our template strand is running from five prime to three prime that is the strand that we're given. So from here, all we need to do is recall our base pairing rules for DNA. Specifically for DNA specifically recall that adenine, that's a pairs with thymine T and vice versa. Well, cytosine C pairs with guanine G and vice versa. So for example, if we look at the DNA strain that we're given, our first base here is going to be adenine, which means that the complementary strand should have thymine up next, we have guanine on our given strand. So that's cytosine on the template or excuse me, complimentary strand, our third base is thymine. So its complement would be at any. After that, we have cytosine whose compliment is guanine, then we have guanine whose compliment is cytosine. After that, we have another adenine whose complement is also thymine and last but not least we have thymine and then cytosine whose complementary bases should be adenine and guanine respectively. So here we have our complementary strand. The sequence is as follows. We have TCGCTAG and as mentioned before, this complementary strand should be running from three prime to five prime because DNA is inherently anti parallel. So all this is to say that our final answer is going to be option A in the multiple choice and there you have it. So with that being said, thank you so very much for watching. And I hope you found this helpful

Write the base sequence and label the 3' and 5' ends of the complementary strand for a segment of DNA with the following base sequences:
b. 5'CCCCTTTT3'

Verified video answer for a similar problem:

Key Concepts

DNA Structure

Base Pairing Rules

5' and 3' Ends

Write the base sequence and label the 3' and 5' ends of the complementary strand for a segment of DNA with the following base sequences:b. 5'CCCCTTTT3'

Verified video answer for a similar problem:

Key Concepts

DNA Structure

Base Pairing Rules

5' and 3' Ends

Write the base sequence and label the 3' and 5' ends of the complementary strand for a segment of DNA with the following base sequences:
b. 5'CCCCTTTT3'