What is complementary strand of DNA of the following single strand DNA sequence 5'A-T-C-A-T-G-C-3' ? How to find it? Explain in detail.

1 Answer
Jul 8, 2018

3'T-A-G-T-A-C-G-5'

Explanation:

DNA is a double helix structure made of phosphate, sugar and 4 nitrogen bases. Your 4 bases are guanine (G), cytosine (C), adenine (A) and thymine (T).

Now, your nitrogen bases actually come in pairs so remember your pairs as GC and AT which means that guanine pairs with cytosine and cytosine pairs with guanine and similarly with adenine and thymine.

Now, you might be wondering about the 5' and 3' at the end of your DNA strand. Remember you have your DNA is made up of 2 DNA strands. One side is known as your 5 prime (5') to 3 prime (3'). These numbers tell you the number of carbon numbers present in your DNA phosphate-sugar backbone.

When they ask you for your complementary base pairs, what they are asking you to do is to find the bases partner ie GC and AT

5'A-T-C-A-T-G-C-3'

BECOMES

3'T-A-G-T-A-C-G-5'