Protein Synthesis Lab Analysis/Conclusion

In order for the body to make proteins, first the DNA must be transcribed into RNA in the nucleus. It is then converted into messenger RNA (mRNA) and sent out of the nucleus to a ribosome. Instead of thymine (T) though, RNA, single stranded, has the base pair uracil (U). The RNA Polymerase pairs the corresponding nucleotides when it is transcribing DNA into RNA. In the ribosome, the RNA is translated from nucleotide "language" into amino acid "language." The RNA is read three letters at a time, called a codon. Each codon codes for an amino acid. These amino acids are joined together to form a protein.

In the lab we experimented with different kinds of mutations that could potentially occur while DNA is being transcribed into RNA. One example of a mutation we tried is a substitution, where one base pair is substituted for another. This mutation had the littlest effect on the final protein. In the worst possible cases it could change just one amino acid, in many cases it could have no effect. The frameshift mutations had a much greater effect, particularly insertion. Almost all of the amino acids were changed when a base pair was inserted, therefore changing the protein entirely. The mutation is worse if a base pair is inserted at the beginning, because more amino acids are changed. 

I chose an insertion when we were asked to choose our own mutation that would make the greatest difference, therefore the greatest damage to the protein. I chose to insert a G directly after the start codon. Inserting a base pair at the beginning made a huge difference to the protein, because it changed all amino acids in the protein except for Met. My mutation changed the protein the most out of all the ones I tried in the lab. This was because the mutation occurred at the earliest time possible. An insertion also changes the amino acids completely. 

An example of a mutation that occurs in humans is Tay-Sachs disease. It is very rare but depending on the onset can be deadly. The autosomal recessive genetic disorder destroys nerve cells in the brain. Gangliosides are fatty substances which are necessary for development of the brain. Normally, gangliosides are broken down, but people who have Tay-Sachs disease lack the enzyme that breaks them down. This destroys the functioning of the nerve cells. There is a mutation on the Hex A gene that causes Tay-Sachs.