Overview: The Genetic information in DNA is transcribed to the RNA and then translated to the amino acid series of a Protein.

A) Step 1: Transcription: Throughout the process of transcription, the information in DNA codons of a gene is transcribed to RNA.

Assume that the gene X has the DNA base sequence 3’-TACCCTTTAGTAGCCACT-5’.

Q1: Illustrate the base sequence of RNA after transcription takes place? Turn this in.

(In this specific ex, suppose that the RNA product doesn’t need processing to become mRNA. In another words, the transcribed RNA becomes mRNA sequence.)

B) Step 2: Translation: Throughout protein synthesis at ribosome, the base sequence of the mRNA codons is translated to amino acid sequence of the protein.

Q2: By using the mRNA which you transcribed above, use the genetic code table to find out the resultant amino acid sequence. Turn this in.

Q3: What is the importance of the first and last codons? What meaning do such codons encompass for the protein synthesis?

C) Mutations: A mutation is defined as the change in base sequence of DNA. This might take place as a ‘mistake’ in DNA replication, for illustration.

Assume that throughout DNA replication, two mutant DNA sequences are generated as illustrated below.

For the two mutated DNA sequences, you will investigate how such changes might influence the sequence of amino acids in the protein.

Q4: For each of the two, you will require to first transcribe the mRNA and then utilize the genetic code table to find out the amino acid sequence.

Turn these in, and state whether the protein sequence modifies for each.

Q5: Then, describe why a change in amino acid sequence might influence the protein function.

Here is the original sequence, followed by the two mutated sequences, 1 and 2:

Original sequence       3'- TACCCTTTAGTAGCCACT-5’
Mutated sequence 1) 3’-TACGCTTTAGTAGCCATT-5'
Mutated sequence 2) 3’-TAACCTTTACTAGGCACT-5’.