i need help again please?

Question

bio again please help...............

2.Suppose one of the bases on the mRNA was chnged. Would the same tRNA molecule still attach to the strand? explain your answer.

3. What would happen to the mRNA strand if an incorrect amino acid was inserted?

Answer 1

if the codon sequence on the mRNA is changed the corrsponding tRNA anticodon will not be able to recongnize it. in fact it may cause disorders like sickle cell anaemia where one of the bases on the DNA coding for glutamic acid codon on the mRNA gets replaced by another base changing it into the codon for a different amino acid called valine.this causes the codon to attract the tRNA of valine and thus causes what is called the 'mis-sense' mutation. i,e, instead of glutamic acid, valine gets inserted in the 6th position of the beta chain of haemoglobin causing sickle cell anaemia. if the new codon formed however is a termination or nonsnse codon the tranlation of protein gets prematurely terminated as the non sense codons have no corresponding tRNA(non sense mutation). there is however another kind of mutation where the new codon formed again codes for the same amino acid( degeneracy of the genetic code). this is called the same-sense mutation.