Question

Har Gobind Khorana and his colleagues performed numerous experiments translating synthetic mRNAs. In one experiment, an mRNA molecule with a repeating UG dinucleotide sequence was assembled and translated.
Write the sequence of this mRNA. Select all that apply:

a) 3'-GUGUGUGUGUGUGUGU...-5
b) 5'-GUGUGUGUGUGUGUGU...-3
c) 3'-UGUGUGUGUGUGUGUG..-5
d) 5'-UGUGUGUGUGUGUGUG....-3

Answer 1

Answer:

c) 3'-UGUGUGUGUGUGUGUG..-5

a) 3'-GUGUGUGUGUGUGUGU...-5

Explanation:

As you may already know, RNA is a single stranded molecule, unlike DNa which is a double stranded molecule. You should also already know that RNA is synthesized from one of the DNA strands, in a process called genetic transcription.

It is important to note that the ends of the DNA strands have "names", one end is called 5 'while the other end is called 3'. In DNA, the 5 'end of one is paired with the 3' end of the other strand. Both DNA and RNA are synthesized in the 5 '------> 3' direction of DNA. In the case of the RNA molecule, this means that the molecule synthesizes will have the ends of its strand formed in the 3 '----> 5' direction.

Accordingly, if an RNA strand is synthesized with a UG dinucleotide sequence, that strand may have the following orientations:

• 3'-UGUGUGUGUGUGUGUG..-5
• 3'-GUGUGUGUGUGUGUGU...-5