Unit 5 Reflection

Unit 5 Reflection

In this unit we learned about the Dogma. First we learned about DNA, which is made up of nucleotides. Nucleotides have three parts- the nitrogen base, phosphate group, and sugar.  DNA is anti parallel, and codes for every trait that you have. To replicate, DNA "unzips" and DNA polymerase rematches it- thus creating two new identical strands, consisting of the bases A,T,C, and G. We also learned about protein synthesis, which consists of two parts- transcription and translation. During transcription, DNA "unzips" and RNA polymerase matches all the spare nucleotides to make an RNA strand- messenger RNA. The RNA code replaces the T with a U. After it is produced, it leaves the nucleus and goes to the ribosome.  Once there, the ribosome reads the messenger RNA in groups of three bases (called codons) and translates it into the language of proteins (amino acids). Third, we learned about mutations, and how they effect proteins. The two main types of mutations are frame shift mutations (insertion and deletion) and mutations involving substitution. Finally, we learned about Gene expression. We learned that every cell in your entire body had the exact same DNA, but not all are expressed. There are different parts which control gene experession, including the promoter, the operon, and the operator. 

I'm good at translating the DNA to RNA and the RNA to amino acids, but I have a little difficulty understanding gene expression and the different parts. I am a better student today because I can now translate DNA to RNA to Amino Acids very very easily and quickly. I also learned better studying techniques, including making tests for myself and hearing the questions out loud instead of reading them. I also made flashcards on certain topics for practice. This works a lot better for me because I am a hands on or listening learner.  

I would like to learn more about how DNA and RNA polymerase work and what other molecules are involved in the unzipping and re matching of DNA. I have no unanswered questions. I wonder about how scientists first discovered protein synthesis and DNA replication, as it happens on such a small scale.

https://en.wikipedia.org/wiki/DNA_polymerase

DNA polymerase and the unzipping of DNA

https://en.wikipedia.org/wiki/Amino_acid

Finished Amino Acid Chain

Protein Synthesis Lab

Protein Synthesis Lab

There are there two parts in the creation of a protein: transcription and translation. During transcription, DNA "unzips," and RNA polymerase re-matches those spare nucleotides, thus making an new RNA strand: messenger RNA or mRNA for short. The messenger RNA leaves the nucleus and travels to the cytoplasm. There, it finds the ribosome. The ribosome reads and translates the RNA 3 bases at a time (these are called codons). It translates it to protein language, or amino acids. Each codon is one amino acid. These chains of amino acids are folded up to make proteins.

nyu.edu/classes/keefer/story/story5.htm

Based on what I have seen, frameshift mutations - both the insertion or deletion of a base - seemed to have the greatest effect on the proteins, as both completely alter the sequence of the bases. When we inserted in a C base to the DNA strand, it mutated the protein so greatly that there was no end and most of the amino acids were changed. When we deleted a T base from the DNA strand, it dramatically shortened the chain of amino acids. The location of the mutation does matter, because if we had deleted a base near the end of the chain then the outcome wouldn't have been as dramatic. The same goes for insertion; if we had inserted a base near the end, then the resulting protein wouldn't have been effected as substantially. The substitution of a base seemed to have the least effect on the protein. When we substituted a C for a T in the DNA strand, there was no effect, as the codon which was changed still translated to the same amino acid. The location of the substitution does not matter, unless the mutation occurs in either the first or last codon- thus changing the start or stop amino acid.  

I chose deletion because in my previous experiment it had the greatest effect on the protein. This mutation didn't alter the protein quite as severely, but still resulted in a protein with no ending. It does matter where the mutation occurs, and if a base closer to the beginning of the amino acid chain had been deleted, then the resulting protein would be almost completely different than the intended version. 

Crohn's disease is a disease caused by frameshift mutation- specifically the insertion of a C base. It is an inflammatory bowel disease. This disease causes you to lose a lot of weight, have pain in your gut,  have a lot of dietary restrictions, and much more. These are symptoms of the disease because it causes swelling in the digestive track as well as ulcers (holes).  

Human DNA Extraction Lab

Human DNA Extraction Lab

In this experiment we questioned whether DNA could be separated from cheek cells in order to study it.  We found that it could be separated, as long as the procedure is followed extremely carefully. It can be observed after precipitation. We know this because we extracted our own DNA, directly after adding the alcohol to our DNA solution. The DNA was white and floated at the top of the test tube.  We knew it could be observed after precipitation based on our prior research.  This data supports our claim because after adding the alcohol we immediately saw the effects on the gatorade solution.

While our hypothesis's supported by our data, there could have been some errors due to timing mis calculations and due to step mix ups. My mixing up the stepping we could have prevented precipitation and messed up the whole experiment. By mis calculating the time we could have also messed up the solution and caused the alcohol to have no effect. Due to these errors, in future experiments I would recommend using a timer instead of watching the clock, and triple checking your procedure.

This lab was done to demonstrate how DNA can in fact be removed by your body cells, and how it is present on every cell that you have.  From this lab I learned the process on DNA extraction which helps me understand the meaning of precipitation.   Based on my experience from this lab, I could apply this extraction technique to other uses such as on fruits like strawberries and bananas.