Protein and Mutated Gene Sequence

Student Name

Mamie Smith Date

August 05, 2011
Questions Student 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):

AUG GGA AAU CAU CGG UGA

Translation (amino acid sequence):

Met (Start) Gly Asp 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):

AUG CGA AAU CAU CGG UAA

Translation (amino acid sequence):

Met(Start) Arg Asp 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):

AUU GGA AAU GAU CCG UGA

Translation (amino acid sequence):

Ile(Start) Gly Asp Asp Pro Stop

What is the significance of the first and last codons of an mRNA transcript? Explanation:
Transcription goes through three steps: (1) initiation that starts at the beginning of a gene, (2) elongation is where the body of the gene metaphoric into growth, and (3) termination stage where a gene dies. The significance of the first and last codons relies on the stages of a gene’s life span. Everything has a point in life where it starts and ends. The importance of genetics is to understand the transformation it goes through.
What meaning do these mRNA codons have for protein synthesis? Explanation:
The mRNA encodes the amino acid sequence of a protein. During the translation, ribosomal RNA combines with other proteins to form a ribosome which amino acids are transported to the ribosome. The combination of mRNA and tRNA converts the mRNA into the amino acid sequence of the protein.

Did the two mutations result in a change in the final proteins? If so, describe the change. Response/ explanation:
A change took place in the final proteins because Isoleucine was added towards the end therefore it couldn’t synthesize the Methionine because of the defect (Audesirk & Byers, 2008).
In general, why might a change in amino acid sequence affect protein function?

Explanation:
Results in the sequence of how a protein functions whenever there’s a change in amino acids depends on the type of mutation. Some of these affects could be from adding or deleting the acids to try and alter the protein. Sometimes a process won’t change a protein if mutation only changes the beta-globin DNA base (e.g. CTC to CTT), then the protein synthesized from the mutation remains the same (Audesirk, 2008).