Unit 5 Reflection

This unit was about what genes are made of and how they are used in our cells. We learned about genetic code and that nucleotides are made up of a nitrogen base of A, T, G or C, a phosphate group and a five carbon sugar called deoxyribose. DNA is copied in order for mitosis and meiosis to take place and it is copied inside of the nucleus. The enzyme helicase unzips the DNA strand into 2 separate strands then DNA polymaerase fills out the complementary strand with matching nucleotides. DNA is the master copy for making proteins and RNA is the disposable messenger copy. For protein synthesis, DNA is transcribed by RNA polymerase into a single strand of mRNA and where the Ts change to Us. Introns that do not code for the protein needed are cut out of the DNA strand so only the exons are left. Then the mRNA goes into the cytoplasm to attach to a ribosome and is read in groups of 3 called codons that code for specific amino acids.
 
 tRNA brings the proper amino acids as the codon is being read by the ribosome. Mutations are changes in DNA when it is copied. Insertions cause the least amount of change to the genetic code because it only messes up one base pair while frameshift mutations like deletion and insertions change the whole reading frame of DNA and every base pair that comes after the mutations. I think of how cells have all genes like a recipe book and cells that are specialized make certain dishes. 
My strengths in this unit were understanding protein synthesis and what enzymes were used. I understood the genetic code because it is similar to computer code. I also got confused when DNA goes to RNA and how the T switches to U.

 One of my weaknesses was understanding gene regulation and what the steps were. I have some problems visualizing it since it is on such a minuscule scale and it is hard to relate to everyday objects that I see and know.

The diagram shown in class is very helpful because I am scared that if I try to draw my own diagram I will get it wrong and study off of a wrong diagram. I want to learn more about how genes are regulated because I find it interesting how the presence of certain material can trigger the production of a specific enzyme.  The process of exons and introns is interesting and how DNA has so many process that happen in order to be used around the cell. I wonder about if DNA messes up when cutting out the introns and creates a big mutation. 

Protein Synthesis Lab Analysis

1. Protein synthesis starts off by the transcription of DNA into RNA in the nucleus. Then, the mRNA texts the nucleus and goes into the cytoplasm to attach to a ribosome. Once the RNA is attached, the code is read by a sequence of 3 bases that make up a codon. tRNA brings the proper amino acid to the codon that is needed. Then the ribosome puts all of the amino acids together to form a chain until the stop codon is read.

2. Insertions and deletions had the greatest effect because they are frameshift mutations and it changes the whole code for the following codons. Substitutions had the least effect because it only changed one base pair and no other bases were changed. It does matter where mutations occur because there are certain codons for start and start that are critical for the structure of proteins. If the change is early in the sequence, then it effects a lot more codons which will change the protein more. If the mutation is later then it doesn't change as many amino acids.

3. I chose 2 deletion because a single deletion had a big effect on making protein. Though it is similar to insertion, my mutation changed the length of the chain of amino acids because it didn't have a start or stop codon since there was a mutation in the first base. It matters a lot where the mutation occurs, and since I put mine at the very front it changed the start codon and the rest after that. 

4. Mutations can affect how our bodies work and look since we are made up of proteins. Mutations can change the original plan of our structure for better or for worse. A mutation like being able to fly would be very useful, and I could go work with the X-men. Some mutations can simply result in visible changes to the body while others change the entire functionality and effectiveness of all systems that help people survive. Progeria is a mutated disease that causes premature aging in children and a reduced life span. It is caused by a point mutations of substituting cytosine for thymine. There is about 1 person mutated for every  8 million births. Most have small, fragile bodies, like an elderly person's. Their face is wrinkled and the head is in larger proportion to their body. People born with progeria live to around mid-teens to early 20s. 

DNA Extraction Lab Conclusion

In this lab, the question was asked how can DNA be separated from the cheek in order to study it. We found that DNA can be separated from the cheek by mixing saliva with salt, detergent, and pineapple juice and then layer the mixture with isopropanol alcohol. When both liquids were separately together in the test tube, DNA rose to where the liquids split and was in suspension. In the information that we collected, we learned that in order to separate DNA, we must homogenize the tissue with a polar liquid. To isolate the DNA,  salt helps precipitation by moving DNA molecules closer together and detergent preforms lysis on the cell membranes. Pineapple juice contains catabolic proteases, which are enzymes that break down histones that DNA molecules wrap around. Alcohol is added to the mixture with the broken down DNA inside, and since alcohol is non polar the DNA precipitated  into an insoluble solid in the middle of the test tube. This shows how different enzymes and solutions can work together to separate DNA from the cheek.
One error that could have happened is that we mixed alcohol with the gatorade mixture. If this happened, then the DNA would have no place in the middle to meet and the solution would be too mixed up. To prevent this, we could pour the alcohol very slowly at an angle with care. Another error that could have happened is that we didn't add pineapple juice. This would mean the enzyme in pineapple juice doesn't break down the DNA and it wouldn't be as visible. To prevent this, we could read the procedure with more care.
The purpose of this lab was to see what DNA looks like and how we can extract it using different solutions. In class, we learned about how the structure of DNA is a long double- helix that in thin like a string, and in the lab we saw that DNA is stringy like clumped yarn. From this lab I learned that by mixing two liquids, I can extract an insoluble solid and I can use precipitation in other situations where I need to separate elements.