Unit 5 Reflection

         This unit was about protein synthesis and different types of mutations. We also learned about how DNA is copied and gene regulation. Protein synthesis is when protein is made through transcription then translation. The first step of protein synthesis is a section of DNA being copied by an enzyme and producing a copy called messenger RNA. The mRNA then leaves the nucleus and moves to the cytoplasm. The mRNA then bonds bonds with a ribosome, which will make a protein. The ribosome reads the first three bases called a codon and that determines which amino acid will go with that base. The amino acids are bonded together, and when the mRNA is done being translated, the amino acid chain folds up to become a protein. There are many different types of mutations such as substitution, deletion, and insertion. However, the worst possible case would either be an insertion or deletion in the very beginning of the sequence. It could cause the protein to change drastically and maybe not even start coding until the middle of the sequence, or not start at all. Gene regulation is when the gene prevents itself from being copied by the RNA polymerase. A strength that I have is understanding protein synthesis because of the lab that we did in class. That lab really helped me understand mutations and their effects, but also how the process of protein synthesis works. However, on the other hand, a weakness of mine is understanding gene regulation. Gene regulation is not something that I understand fully yet, and I still have trouble knowing the process of it. I am definitely a better student than I was before this unit because I learned more about these processes in detail, and I think that I can now explain to my peers almost all of the topics of this unit. I want to learn more about mutations and the conditions/diseases they cause because I think it's so interesting how one extra amino acid added or taken out can cause such a big change to the protein. An unanswered question that I still have is how complicated gene regulation can get in humans. I still wonder about how many mutations can be caused in one sequence of bases or whether there is a limit to as how many can occur or not.
          According to the Vark Questionnaire, I learned best when I listened to other people talking and when I saw diagrams and pictures. Because of this new information, I studied playing to my strengths and it actually helped me a lot. I did pretty well on the test and it the most recent test actually ended up being my highest test score. I learned that studying by looking at pictures and listening to vodcasts really helped me soak in all the information. I will definitely study like I did for the most recent test for the upcoming final.

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.

DNA Extraction Lab

          In this lab, we asked the question "how can DNA be separated from cheek cells in order to study it?" We found that DNA can be separated from cheek cells in order to study it. The first step of the lab was to scrape the sides of our cheeks with our teeth. We then put a few mL of gatorade in our mouths and then swished it around vigorously. When we swished the gatorade around in our math, we homogenized the cheek cells. We then spit the gatorade back out into our cup and put it in our test tube. After that we added about 10 drops of pineapple juice and soapy water with a pinch of salt. The pineapple juice acted as the enzyme, the soapy water lysed the cell membrane, and the salt was added to make the DNA nonpolar. The salt also facilitated the precipitation. After we added the salt, dish soap, and pineapple juice, we then flipped the test tube upside down about six times. We then let the test tube rest for about five minutes. Last, we added cold alcohol to the test tube, making sure not to mix the alcohol with the mixture. After we added the alcohol, the DNA started to float up into the alcohol. This evidence supports our claim because it shows that the DNA from our cheek cells can be seen using this procedure.

          While our DNA could be extracted from our cheek cells, there could have been errors due to us not scraping our cheeks with our teeth enough and the alcohol mixing with our solution. If we didn't scrape our cheeks enough, then there would have a been a very small amount of DNA or maybe even no DNA to show up doing the experiment. If we mixed the alcohol with our solution then there would not have been enough non polar alcohol to precipitate the DNA. Due to these errors, I would recommend to make sure to scrape the sides of your cheeks thoroughly and to make sure the alcohol is cold and to add it to the mixture at an angle so it doesn't mix as easily.
          This lab was done to demonstrate how DNA can be extracted from our cheek cells. From this lab I learned how DNA could be extracted which helped me understand the concept of DNA replication and the central dogma. Based on my experience from this lab I would apply this to another situation by teaching someone how to extract their own DNA from their cheek cells in order for them to understand the concept of DNA better.