U3Ip Graphic Organizer

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QuestionsStudent Response

Part I

Original DNA Strand:

3’-T A C C C T T T A G T A G C C A C T-5’

Transcription (base sequence of RNA):

5’-AUG GGA AAU CAU CGG UGA-3’

Translation (amino acid sequence):

Met Gly Asn His Arg Stop

Mutated gene sequence one:

3’-T A C G C T T T A G T A G C C A T T-5'

Transcription (base sequence of RNA):

5’-AUG CGA AAU CAU CGG UAA-3’

Translation (amino acid sequence):

Met Arg Asn His Arg Stop

Mutated gene sequence two:

3’-T A A C C T T T A C T A G G C A C T-5’
Transcription (base sequence of RNA):

5’-AUU GGA AAU GAU CCG UGA-3’

Translation (amino acid sequence):

Ile Gly Asn Asp Pro Stop

What is the significance of the first and last codons of an mRNA transcript?
Explanation: The first codon of an mRNA transcript is called initiation codon and it initiates the translation process, which is necessary for formation of a protein. The last codon is known as a Stop codon as it stops the translation process to end the addition of amino acids to protein chain. In absence of Stop codon the protein formation is never completed as there would uninhibited addition of amino acids. What meaning do these mRNA codons have for protein synthesis?

Explanation: The mRNA codon sequences specify for respective amino acid. More than one trinucleotide sequence can code for single amino acid but not the other way. This means the codons on DNA are transcribed to mRNA which in turn code for specific aminoacid. This amino acid sequence translates into protein by protein synthesis. Thus codons determine the protein structure and type.

Did the two mutations result in a change in the final proteins? If so, describe the change.
Response/ explanation: Yes. As the sequence of amino acids in Mutation 1 is different from original strand, the protein formed is different. The protein can be abnormal. In Mutation 2, protein fails to form as...
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