hehehe..since this subject is da most scariest one so here it goes...
Lecture 2 - mRNA processing n translation...ok lets start with mRNA processing..initial mRNA from a gene is called primary transcript or pre-mRNA. it is immature n not fully functional..pre-mRNA will under go series of modification which called mRNA processing before they when to translation process..modification includes ;
1- RNA splicing - cutting da introns n splicing the mRNA in several location to produce numeral coding sequence.
2- 5' cap - guanine base containing a methyl group is added . the structure formed plays important role in ribosome recognition of da 5' end of da mRNA molecule during translation.
3- polyadenylation - a string of adenine nucleotide around 100 - 300 nucleotides in length is added to the 3' end of da mRNA creating a poly A tail. the tail protects mRNA from degradation in da cytoplasm, increasing da stability n availibility for translation.
by following those methods, a mature mRNA leaves da nucleus n enter cytoplasm for translation process.
translation - this process involves three major components, messenger RNA (mRNA), ribosomal RNA (rRNA) n transfer RNA (tRNA). in translation process there are also three stages involve which is initiation, elongation n termination.
Initiation - small ribosomal subunits binds to 5' end of mRNA molecule by recognizing da 5'cap of mRNA.. initiation factors guides da small subunits to da mRNA..small subunits will moves along until it encounters da start codon, AUG.. da start codon will paused, small subunits wait for da correct tRNA a.k.a initiator tRNA to came along..tRNA has
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