Question

7. (6 points) One strand of a section of DNA reads 3-TAGTATGCTAgaatATTTGA-3' Suppose that an mRNA is transcribed from the complementary strand (not shown) to this DNA. What will be the sequence of the pre-mRNA (make sure you label the 5' and 3'ends)? BUCO BUCO DUCO DUCO B. The lowercase letters in the sequence above represent an intron. Starting at the ATG, what would be the protein sequence once the intron is properly removed? с Two mutations occurred. 1) A deletion of the fourth coding nucleotide (a cytosine) 2) A substitution in the nucleotide just prior to the start codon. Assuming the protein is still made, what would be the change in the amino acid sequence of the protein?

Answer 1

starting codon 5 - UAG UAU GCU AAU UUGA - 3' → Sequence of M-RNA MUTATION 11 A deletion of the fourth Coding nucleotide (acytosine) 5'- UAG? UAU GUA ANU UGA -3' MUTATION 12 A substitution in the nucleotide I just prior to the start codon starting codon 5-UA JAU GUA AUU UGA - 3' TRANSLATION Tyr- Val - Ile- The protein chain contains three amino acids, The sequence of ammino acids is protein after Changed in the mutation.

AGTATGCT Agaat ATTTGA-31 3- ATCATA CGAT etta TAAA CT-5' Non Template strand Template strand TRANSCRIPTION The sequence of mRNA is complementary to the sequence of Template strand of DNA. - UAG UAU GCUAgaam A UUUGA - 3 Sequence of pre-mRNA Infrons splicing Introns are removed during splicing and Exons (uppercase letters) are joined together. UAGUAY GCY AAU UUGA-31 - Sequence of an starting codon Translation Genetic code are given in the table Tyr - Ala - Asn-Leu - Sequence of prethain peptide bonds L four ammino acids. contains The protein