Question

Methyl guanosine triphosphate is associated with
a) Point Mutation
b) Tautomerism
c) Capping
d) Okazaki Fragments
e) Tailing

Answer 1

Hint: The purpose of methyl guanosine triphosphate is to study the structure and mechanism of the mRNA caps with respect to protein synthesis.
Capping utilizes the following enzymes:-
-Guanylyltransferase
-RNA triphosphatase
-methyltransferase
Presence of a 7-methylated guanosine cap is an essential factor for splicing.

Complete answer:
Methyl guanosine triphosphate is associated with capping.
Capping occurs at the beginning of transcription in the nucleus. It consists of the addition of a 7-methylated guanosine cap at the 5’ end of the mRNA. Capping offers protection to the mRNA against phosphatases and other nucleases.
Capping with 7-methylguanylate begins at the unaltered 5’ end of the RNA molecule and stops at the triphosphate group. Capping begins as the pre-nascent RNA is being synthesised before transcription is completed.
Tautomers are isomeric compounds which differ in the position of the protons and electrons.
Point Mutation is a mutation where only a single nucleotide base is inserted or deleted from the genome.
Okazaki Fragments are short sequences of nucleotides from DNA that are discontinuously synthesized and linked together by DNA ligase which creates the lagging strand during replication.
Tailing is the addition of a chain of adenine nucleotides at the 3’ end of the mRNA.

Therefore option c) is the correct answer that is capping.

Note:
The 5’ cap which is found on the 5’ end of an eukaryotic mRNA molecule is made up of a guanine nucleotide. This guanosine is methylated at the 7 position forming methyl guanosine triphosphate. Capping has the following functions:
-Promotion of translation
-Prevention of exonuclease degradation
-Monitoring of nuclear export
-Advancement of 5’ proximal intron excision