Question

Retum M WANG: Meere you cover be your won b ig Please identity the mRNA and polypeptide sequence from the below DNA using the genetic codon table. (Note: the direction of mRNAS important Keep in mind that the genetic codons are read from 'to 3 direction on ANA. Also, RNA bases are AUCG instead of A.T.C.G POCO POCOOC 3-GTT - TAC - CTT-CTC - TGC - TCA - GAC AIC GLA 45 (Template strandi B-CAA - ATG-GAA-GAG - AGG- AGT-CTG - TAG-CGT 3 Non-template/Coding strand mRNA: - GUU UAC CUU CUC UCA GAC AUC GCA polypeptide: N-VAL TYR LEU LEU UCC

please help with #4 and #5

question 5 of 5

the cross lines indicate deletion of the nucleotides. what type of mutation is this? what is the resulting polypeptide sequence?

3'- GTT - TAC - CTT - -CTC--TCC -TCA -GAC - ATC -GCA -5' (template strand)

5' - CAA - ATG - GAA - -GAG--AGG - AGT - CTG- TAG - CGT - 3' (non-template/coding strand)
answer: It's a ___________________mutation.

Final polypeptide sequence is N' - Met - GLU _______________     _____________   ______________     ______________ -C'

please note the CTC - T has a line through the middle of it.

please note the GAG- A has a line through the middle of it.

Answer 1

Question 1)

You have to make complementary RNA with respect to template strand.  

And if you are using coding strand for mRNA sequencing, then T in coding strand should be replaced by U.

That's why mRNA sequence is :

5' CAA AUG GAA GAG AGG AGU CUG UAG CGU 3'

AUG is the start codon. This is the codon where amino acid synthesis occur. UAG is the stop codon. At this site polypeptide synthesis stops.

Polypeptide: N met glu glu arg ser leu C

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Question 4)

After mutation following mRNA is formed:

5' CAA AUG GAA UAG AGG AGU CUG UAG CGU 3'

Now look in the mRNA codon table, you will find that GAG code for glu( glutamine) where as UAG acts as stop codon. It will not encode any amino acid.

Answer: amino acid changes from glu ( glutamine)   to  no amino acid (×). It's a nonsense mutation.

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Question 5)

Following mRNA is formed after the deletion of nucleotide:

5' CAA AUG GAA GGA GUC UGU AGC GU 3'

It's a frameshift mutation.

( because number of nucleotide are deleted which leads to change the sequence if codon)

The following polypeptide is formed :

N met glu gly val cys ser C