Download Lab - Protein Synthesis

Biology Lab
Transcription & Translation
Background:
The coding sequence (5’  3’ “antisense”) of DNA below leads to the production of a specific protein. That
makes it a gene. The gene was sequenced from samples taken from healthy human patients. As a genetic
researcher you must first transcribe the sequence into an mRNA sequence. Then, using the genetic code, you
must translate the mRNA into the sequence of amino acids which is the 10 structure of the protein. The mRNA
is read by the ribosome in the 5’  3’ direction. If you were given the 3’  5’ “sense” or “template” DNA
strand you would have to transcribe each A to a U, T to an A, C to a G, and G to a C to find the mRNA
sequence. Since this is the 5’  3’ “antisense” strand and the mRNA is also 5’  3’ you only need to replace
each T with a U to find the mRNA sequence.
Materials and Methods:
Gene sequence from healthy patientsatgttaatct tttacgttat tgccgtcttt agaaagaaat atccaacgag acgggaaatg gattcaccaa aaactggtaa attgttacac attctcaacc
caaaatggag gtacaatacc tacaccttta tcccgaacct acaatcgatt gaacgggttt acaatgtcga ttgtctttca ccatgtgggc tctacggatg
ggtccaaaca gactggagtc cggacacgag aaatatactc aagtacgatt gtgagtctac tacacgatcc gtgtttttaa tctataatgt ggttaaaggt
The same sequence taken from cancer patients has an insertion point mutation at the 30th nucleotide which is an
inserted thymine nucleotide.
atgttaatct tttacgttat tgccgtcttt Tagaaagaaa tatccaacga gacgggaaat ggattcacca aaaactggta aattgttaca cattctcaac
ccaaaatgga ggtacaatac ctacaccttt atcccgaacc tacaatcgat tgaacgggtt tacaatgtcg attgtctttc accatgtggg ctctacggat
gggtccaaac agactggagt ccggacacga gaaatatact caagtacgat tgtgagtcta ctacacgatc cgtgttttta atctataatg tggttaaagg t
1. Transcribe the DNA sequences into mRNA sequences.
2. Translate the mRNA sequences into the amino acid sequences using the genetic code.
You should discover the 10 structure of the wild type and mutated proteins.
Biology Lab
Transcription & Translation
Results:
Insert the Wild DNA Sequence:
Insert the Wild mRNA Sequence:
Insert the Wild Amino Acid Sequence:
Insert the Mutant DNA Sequence:
Insert the Mutant mRNA Sequence:
Insert the Mutant Amino Acid Sequence:
Biology Lab
Transcription & Translation
Questions:
1. What is the purpose of this experiment?
2. What is the “start” codon?
3. How many proteins (polypeptides) were produced from the wild dna sequence?
4. What was the length of the protein(s) produced from the wild dna sequence? (Number of amino acids in
each polypeptide.)
5. How many proteins (polypeptides) were produced from the mutated dna sequence?
6. What was the length of the protein(s) produced from the mutated dna sequence? (Number of amino
acids in each polypeptide.)
7. What is your hypothesis as to the extent of the protein mutation and how this DNA point mutation leads
to carcinogenesis? Be as detailed as possible and use an extra sheet if necessary.