Name:______

Protein Synthesis

This is just a short gene of a plant. Transcribe and translate this gene. Begin with the promoter site and end with the termination site. There are no introns in this gene. Mature mRNA will include the cap and the tail, while mRNA will not. Mature mRNA will not include introns, while mRNA will.

DNA / 5'TATACCATGACTAAACGACAATACCTTTTCACTGGGGATGACCCAATTCTTGATGAATTACATGGCGCTGCTTAACGGCACAATAAA3'
3'ATATGGTACTGATTTGCTGTTATGGAAAAGTGACCCCTACTGGGTTAAGAACTACTTAATGTACCGCGACGAATTGCCGTGTTATTT5'
mRNA
mRNA
Mature
Protein

This is a fungal regulatory gene. Transcribe and translate this gene. Begin with the promoter site and end with the termination site. Make sure to add the cap and the tail to the mRNA. Look for the intron. Do not include the intron in the mRNA. On the test I will not give you this last piece of advice. Mature mRNA will include the cap and the tail, while mRNA will not. Mature mRNA will not include introns, while mRNA will.

DNA / 5'AAATATACGGCAATGAAAATAACGATCTAGTATTATTAGTTCATGCCGCGCTTGATTCTGATTAATAAA3’
3’TTTATATGCCGTTACTTTTATTGCTAGATCATAATAATCAAGTACGGCGCGAACTAAGACTAATTATTT5’
mRNA
mRNA
Mature
Protein

Original mRNA (From DNA)

There are many types of mutations. Below are a few examples of mutations to one gene. Translate the mRNA below. Below is a piece of mRNA. We will use the mRNA and its protein as a point of comparison.

mRNA
Mature / GUAUACGGCAAUGAAAAUAACGAUCUAUUGAUUCUGAUUAAUAAAAAAAAAAAAA
Protein

Point Mutation

A point mutation, or substitution, is a type of mutation that causes the replacement of a single base nucleotide with another nucleotide. Translate the mRNA below. What was the mutation in mRNA? Understand that there would be a similar change in the DNA

mRNA
Mature / GUAUACGGCAAUGAAUAUAACGAUCUAUUGAUUCUGAUUAAUAAAAAAAAAAAAA
Protein
Mutation in mRNA The adenine at position _____of the coding mRNA was changed to an ______resulting in the amino acid ASN instead of the normal _____.

The above mutation is also called a missense mutation. Missense mutations are types of point mutations where a single nucleotide is changed to cause substitution of a different amino acid. This usually produces a non-functional protein as in the case of sickle-cell anemia.

Silent Mutation

mRNA
Mature / GUAUACGGCAAUGAAAAUUACGAUCUAUUGAUUCUGAUUAAUAAAAAAAAAAAAA
Protein
Mutation in mRNA

Silent mutation is a point mutation in a sequence of DNA, and therefore mRNA, that does not result in a change to the amino acid sequence of a protein. Use the answer format from the point mutation problem to explain the mutation in mRNA and its effect on the resulting protein.

Nonsense Mutation

mRNA
Mature / GUAUACGGCAAUGAAAAUAACGAUCUAAUGAUUCUGAUUAAUAAAAAAAAAAAAA
Protein
Mutation in mRNA

A nonsense mutation is a point mutation in a sequence of DNA, and therefore mRNA, that results in a premature stop codon, or a nonsense codon in the transcribed mRNA. This usually results in a nonfunctional protein product. Use the answer format from the point mutation problem to explain the mutation in mRNA and its effect on the resulting protein.

Have the Lab Instructor or T.A. check your work and have them initial here ______.