Unit 5 Reflection

The theme of Unit 5 was DNA and how it affects our daily lives. It went over concepts such as what DNA is, how it is replicated, how DNA is used to create proteins, as well as how genes are regulated and expressed in cells. The main understanding of this unit was to understand how DNA affects and controls our whole lives. This unit taught us how to look at the big picture of DNA and not simply what it is, but how it in fact affects our whole bodies and how are genes are expressed to create organisms. My main strength in this unit was my understanding of how DNA is used to create. Through the process of protein synthesis, in which the DNA is transcribed to RNA and then translated to proteins, DNA is changed into proteins which act as the phenotype and expression of genes. The enzyme RNA polymerase reads the DNA split strand and changes the base thymine with uracil, create a single RNA strand. The ribosome then reads the RNA strand and reads it one codon at time (pairs of 3 bases which code for a specific acid) and creates the protein. The protein synthesis lab gave a visual representation of the process which helped me to understand it and allowed me to experiment with mutations and how they affect genes. One concept I had a hard time understanding was how genes are regulated and expressed due to the complexity of the concept and how it is intertwined with protein synthesis. The diagram during the Lac opperon do now gave me a greater explanation because it provided a properly labeled visual diagram which incorporated all the vocab from this concept. My notes during the vodcast were sub par which really hurt my understanding.

https://en.wikipedia.org/wiki/Protein_biosynthesis#/media/File:Ribosome_mRNA_translation_en.svg

I learned that it is important to look into the deeper meaning of things and their effect rather then just taking them for face value. This was seen with DNA, as I learned about the actual effects of DNA rather than just accepting that there is something called DNA. I also learned that you should be willing to ask for help, as I asked my brother to help me with the concept of protein synthesis since he has taken biology before and is a biochemistry major.

http://biosocialmethods.isr.umich.edu/wp-content/uploads/2014/09/central-dogma-enhanced.png

From the Vark questionnaire I learned that I am mainly a visual and reading/writing learner, which is why I have started to learn more by using notes and drawing diagrams which give me a visual representation of certain concepts. I wonder how organisms were first able to create protein and other molecules when they first evolved since they had to first create certain organelles with out these processes. I feel that I am a better student today since I truly understand DNA and how it effects organisms, rather than in 7th grade biology where I new what DNA was but what is was and how it was different than RNA.

Protein Synthesis Lab Analysis

-       The process of protein synthesis changes DNA into RNA, and then into proteins. The steps of this include transcription and translation. During transcription, RNA polymerase binds to the DNA and separates the DNA strands. RNA polymerase then uses one strand of DNA to as a template and attaches the corresponding nucleotide to create the strand of RNA. The base thymine is switched with the base uracil. The new RNA strand then travels from the nucleus to the ribosome. In translation, the ribosome reads the codons (pairs of 3 bases) to create a specific amino acid, which is then attached to a long string to create a protein.

     Changes in the base pairs of DNA molecules can have a major effect depending on the type of mutation that occurs and where in the DNA sequence it occurs. The 2 types of mutations are point mutations and frameshift mutations. Point mutations can be harmless and may only change one codon, though the amino acid coded is still the same. Frameshift mutations can drastically alter the DNA sequence and change the proteins created. The insertion and deletion of bases change all of the codons after the change and greatly affects which amino acids the codons code for due to them all being changed. A frameshift mutations earlier in the sequence is the most harmful as it has the most codons to change.

    

    The mutation that we chose for our was a deletion of a base near the beginning of the sequence. We chose this mutation since it was a frameshift mutation and we believed that it would cause the most damage. Compared to other mutations, this one changed the most base codons and changed the most amino acids, creating different ones and getting rid of the stop codon. It matters where the mutation occurs because earlier mutations change all the ones behind them and have a greater effect.

    One real life mutation that occurs in human organisms is sickle cell anemia, which is the result of point mutation in one of the nucleotides for the protein of hemoglobin. The mutation causes the red blood cells to distort and form clots, greatly endangering the body.

Human DNA Extraction Lab Conclusion

In this lab we asked the question of "how can DNA be separated from cheek cells in order to study it?" We found that you can separate DNA from cheek cells through the steps of homogenization, lysis, and precipitation, which is where the DNA first becomes visible. Our claim was correct since we used this process to extract DNA, and the DNA came out in creamy white clumps once the alcohol was added on top of the solution, which acted to draw out the precipitate (DNA). Our qualitative data supports our claim since the DNA is supposed to float to the top since it is nonpolar and the alcohol is polar, so it floats the top (precipitation) . The protocol for extracting DNA that we followed properly worked, which allowed us to extract the DNA.

While our hypothesis was supported by our data, there could have been errors due to an incorrect ordering of the lab procedure and improper measurements of liquids and enzymes added to the solution. In the lab, we were required to properly order the steps of the lab according to the steps of DNA protocol. We decided to put soap into the solution before salt, which incorrectly follows the procedure since soap is added to lyse the cell membrane and emulsify the lipids, while salt is used to facilitate precipitation of the DNA, and since lysis comes before precipitation, so our ordering was wrong. This could have had a major effect, as the DNA may have not been properly extracted and we may have not gained enough of the DNA. Improper measurements of solutions could have effected the data since unequal measurements could have changed the solution and the way it effected the DNA. Due to there errors, in future experiments I would recommend that the protocol be given to us beforehand so that everyone follows the same procedure, but is is impossible get rid of the improper measurements due to the chance of human error.

This lab was done to demonstrate how DNA can be extracted from cells and how to create a procedure for labs based off given information. From this lab I learned the three basic steps of DNA extraction (homogenization, lysis, and precipitation), which helps me understand the concepts of how DNA is extracted and how different solutions interact with the molecules within DNA. Based on my experience from this lab, I can apply my knowledge to different labs involving DNA and now know how to create a lab procedure by identifying different given parts and putting them in order.