Protein Synthesis Lab

          In order to make a protein, the gene first has to be transcripted. A section of DNA, or a gene, is copied by an enzyme. The copy that is produced is called messenger RNA, or mRNA. The mRNA then leaves the nucleus and travels to the cytoplasm. Then, the copy is used to make a protein in a process called translation. The mRNA bonds with a ribosome to make a protein. The ribosome then reads the first three bases called a codon, and determines which amino acid will correspond with that specific sequence. Each amino acid that is added is determined by the codon read by the ribosome. The amino acids are bonded together and when the mRNA finishes translating, the amino acid chain folds up and becomes a protein.

          The mutation that seemed to have the greatest effect in our lab was deletion, and the mutation that seemed to have the least effect was substitution. During some cases, substitution can cause no change to the amino acids determined and the protein can stay the same. However, in other cases, substitution can cause the protein to change a lot. Insertion could also cause very similar effects as deletion. It is very important where the mutation occurs. If it happens near the beginning of a sequence, then it could become very harmful, whereas if it happened near the end, there would be less of an effect. It would be different if the T that we substituted for C were near the end of the sequence because then it would have caused less amino acids to change; therefore, leaving the protein mainly unchanged.

          When we got the chance to choose our mutation, I chose deletion because I wanted to see how much it would change if I deleted the very first base in the sequence and then again later on. This mutation was different than the others ones we tried because this sequence didn't even start coding until near the middle of the bases. There was no "met" amino acid to tell the ribosome to start coding until it got to the middle of the sequence. It does matter where the mutation occurs because if I hadn't changed the first base and say I changed the last, then the protein would have had a start codon in the beginning.

          If proteins make our bodies work, and proteins are determined by the sequence of amino acids, a mutation could affect my life by causing a disease and my body potentially not behaving correctly. There could be a serious disease caused by one single base being inserted, missing, or substituted that could alter the function of my whole body. An example of a disease caused by a single mutation is Tay-Sachs disease. It is very rare, inherited disease that causes the destruction of nerve cells in the brain and spinal cord. Symptoms usually appear from around six months old, and there is no cure. The disease is inherited in an autosomal recessive pattern.