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From Genes to Proteins, Mutations

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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'-AUGGGAAAUCAUCGGUGA-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'-AUGCGAAAUCAUCGGUAA-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'-AUUGGAAAUGAUCCGUGA-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 encode the start sequence which is usually methionine.
The last codon encode the stop codon that is usually signal the stop of the transcript
What meaning do these mRNA codons have for protein synthesis?
Explanation:

The mRNA codons are usually in triplet code that codes for amino acids. There can be different codons that code for the same amino acids.

Did the two mutations result in a change in the final proteins? If so, describe the change.
Response/ explanation: yes, in the first mutation, there is a change in one of the amino acid in the final protein from glycine to arginine.

Met-Gly-Asn-His-Arg-Stop normal
Met-Arg-Asn-His-Arg-Stop mutated sequence 1

In mutation two, there is a change in three amino acids. The start codon methionine is change into isoleucine ; the histidine is ...

Solution Summary

Transcription, translation , and protein synthesis is the central dogma of molecular biology. Transcription is when DNA is converted to mRNA with the help of DNA polymerase. The mRNA is then translated into protein by the process of translation. In some cases, there are mutation in the DNA that would produce different mRNA transcript and different proteins.

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