Question

If the sequence of the template strand in a transcription unit is written as follws :
5' - ATGCATGCATGCATGC - 3'
what is the sequence of mRNA?

Hint:

Always remember: RNA contains Uracil ($U$) instead of Thymine ($T$).

Answer 1

Step 1: The mRNA is synthesized complementary to the template strand but in the opposite polarity.
Step 2: If the template is 5' to 3', the mRNA will be 3' to 5'. Adenine ($A$) pairs with Uracil ($U$) in RNA, and Cytosine ($C$) pairs with Guanine ($G$).
Step 3: Result - The complementary sequence for 5' - ATGCATGCATGCATGC - 3' is:
3' - UACGUACGUACGUACG - 5' (or 5' - GCAUGCaugcaugcau - 3').