Unit 5 Reflection

   In unit 5, we learned deeper into how and what DNA is. DNA is constantly being replicated. DNA is composed of a nitrogen base(A,T,C,G), a phosphate group, and a sugar(deoxyribose). DNA is antiparallel and is made of a two strands, double helix. A goes with T and C goes with G. We also learned about RNA, which is only one stranded. A RNA Polymerase will attach onto a DNA strand and start transcribing the DNA, then it shoots out the mRNA with the same code. In mRNA the T is switched with U. The mRNA then leaves the nucleus and goes to the ribosomes. The ribosomes then translate the code into amino acidsl, which are the ones that create the proteins. We also learned more about mutations. Mutation can be natural but mostly caused by something. There is substitution, which changes one base into another, insertion, meaning one base is inserted into the code, or there is also deletion, meaning one base is deleted from three code. The most harmful is deletion, for it is a frame-shift mutation. The more changes in the  DNA, the more there is a difference in the protein being created. Last but not least, we learned about gene expression and gene regulation. Gene expression is how one gene is expressed in different areas of your body. Gene regulation is how gene are regulated on how they are being expressed. Eukaryotic regulation are much more complicated. There are histones and nucleusomes. I did not understand how gene regulations worked very well, for the process is very complicated and there is a lot of components. My strengths were in translating the codons.

  From this unit, I have grown a lot in relation with everything that has to with DNA. With this unit and these many labs, I have learned about how and why DNA is how it is. I have also learned to challenge myself in learning more complicated subjects that take time to fully understand. The many labs we preformed have help me understand and I am also better at following and creating labs. I am a better student, for now I have worked and learned more challenging units and can now better understand and also no know how to learn subjects that I may not understand on the first try.

Protein Synthesis Lab

  To create proteins, there are two steps, transcription and translation. First the DNA is copied by an enzyme, it becomes mRNA. The mRNA will then travel out the nucleus to reach the ribosomes. mRNA bonds with the ribosome , which reads the sequence of three bases at a time, it is called a codon. Each codon is translated to an amino acids. The amino acids are bonded together to make a protein.

   By changing the bases of DNA, the protein could vary a bit from the original protein or it can be changed greatly. The mutation  with the greatest effect was deletion, for it caused the sequence to be completely changed after it being deleted. It also caused there to be no stop and the codons changed a lot from the original. In  ours, the sequence just stopped in the middle of it. Substitution tended to be the less harmful, for it only changed one codon at the most, but sometimes, it did not even change, for it translated to the same amino acids. A mutation that occurs in the beginning, if it is a deletion or insertion, will have more harmful effects, for the sequence from near the beginning will change widely from the original. One that occurs at the end, will only affect the end of the sequence. If the T was at the end, the sequence would not have changed a lot for only the end would the T have become another letter.

   We chose to test deletion another time, for it was the most harmful of all the mutations. This mutation related to the others because we specifically chose to delete to of the letters T, we mostly modified the T in the other mutations. Instead of only deleting one base, we decided to delete two of them, one near the start and one near the end of the sequence. With this, we saw that the most damage occurred directly near the beginning, this shows that where a mutation occurs, directly affects the results. The closer to the beginning, the more harmful the mutation becomes.

    Some mutation can affect our lives greatly. Though some are not harmful, some others are. A mutation could be very small and just cause some minor problems, or it could cause your body to not function correctly and make your cells not work correctly. Though there are many harmful mutations out there, an interesting and very rare mutation related disease is called Progeria. Progeria causes the child affected to seem to age a lot. Most children with Progeria die at the age of 13, but some do reach their 20's. Their cells mature very fast, and their bodies look and act like if they were an elderly person. Progeria only occurs to one out of around 80 million of children. 

 

DNA Extraction Lab

  In this lab, we asked the question," how can DNA be separated fro cheek cells in order to study it?" We found that to extract the DNA from our cheeks, we had to create three parts, homogenization, lysis, and precipitation. To accomplish homogenization, we needed to retrieve the samples using a polar liquid. We used Gatorade, which became one with the DNA. We then used that mixture for lysis, which we added salt, then soap. This caused the DNA to be completely released into the mixture. We also used pineapple juice, which contains catabolic proteases, to further break down the proteins, the juice was used as an enzyme. Lastly, we added the wiping alcohol, which ended the precipitation stage, the DNA had finally been extracted. After we added the alcohol, the DNA started to float up to where the two liquids met, for the alcohol is nonpolar while the mixture was polar. The DNA was very small and had been dyed red by the Gatorade. Like what was taught in Unit 2, polar and nonpolar mixtures separate, so the DNA floated to the middle. We also learned in Unit 5 that DNA is nonpolar. This data supported our claim because the reason why the DNA was extracted was because the of DNA's polarity and how it reacts when mixed with polar liquids/solutions.

   While our hypothesis was supported by our data, there could have been errors made due to how my group and I had to in some ways create our own procedure by rearranging the steps, so that the experiment would work out. This could have affected the results because we may not have done the experiment correctly, which could have led to no data at all. Another error that may have been made was how we may have measured each/some of the liquids wrongly. We could have accidentally put in 11 drops instead of 10 drops which could have possibly led to the experiment not working out, and no DNA being extracted. These errors could have been avoided through having been given the instructions given at the beginning and that the measurements could have been more precise and that we could have been more cautious.

    This lab was done to demonstrate how homogenization, lysis, and precipitation could be used to extract the DNA from our cheeks. We used what we had learned from the previous vodcast about DNA and all the prior knowledge we had accumulated over the past units to form an experiment and extract our own DNA. From this lab, I learned about the properties of DNA. I also learned about how scientist extract/ absorb DNA. Based on my experience from this lab,  I better understand how the properties of DNA, such as polarity, affect it.