Wednesday, December 9, 2015

Protein Synthesis Lab

In order to make a protein, the first step is having the DNA sequence read and transcribed into RNA. RNA polymers read and copy the DNA code for a protein as an mRNA copy. Base pairing rules apply, but U replaces T. The next step is translation. MRNA arrives at the ribosome, which reads mRNA three bases at a time, or reads the codons, and translate DNA language (A,G,C,U) into protein language (amino acids)
 
https://upload.wikimedia.org/wikipedia/commons/thumb/3/38/Protein_primary_structure.svg/2000px-Protein_primary_structure.svg.png

Deletion and insertion seemed to be the most changing forms of mutation. Substitution effected the protein code the least. Where the mutation occurs does matter for all the forms of mutation. The earlier the code, the most damage deletion and insertion do. Substitution just need to change an essential nucleotide to make any sort of difference.

https://upload.wikimedia.org/wikipedia/commons/5/50/Mutation_par_substitution.png

I chose the insertion mutation because it seemed to have changed the amino acids the most. Insertion did change the amino acids almost as much as deletion did, and it definitely changed more than substitution. Since I inserted a new nucleotide in the very beginning, it had the biggest effect on the sequence, showing how important where the mutation occurs is.

https://upload.wikimedia.org/wikipedia/commons/thumb/6/6d/RNA-codons-aminoacids.svg/2000px-RNA-codons-aminoacids.svg.png

Mutations could greatly affect my life. They could constrict me from doing many things and functioning properly, or they could be minor and not have to big of an effect on my life. For example, huntington disease is an inherited mutation in which nerve cells in the brain break down over time. Huntington's disease is an autosomal dominant gene. There is a 50% of children inheriting the gene.

http://hdsa.org/wp-content/themes/hdsa/images/img_HD2.png

Unit 5 Reflection

This unit was focused on DNA and replication of it. Themes and essential understandings were centered on what mutations are (a change in the DNA codes) and how they were caused (substitution and framshift mutations). They were also centered around transcription (the process where RNA polymers read and copy the DNA code for a protein as mRNA copy) and translation  of DNA.
Gene expression, which is the process of a gene being used to produce a gene product, and gene regulation, a mechanism used by cells to increase or decrease the expression of a gene, were my strengths because they made a lot of sense to me and I could picture these very well. It was hard remembering the what exons, sequences that are "expresses," and introns, sequences that are cut out, are because they sound very similar. Also, not getting promoter, the location on DNA where RNA polymerase attaches, operon, a series of genes used to control the expression of a single gene, and operator, a "switch" or segment of DNA at the start of a gene that prevents or allows RNA polymerase from attatching and reading the gene, mixed up is pretty difficult. The pictures below help me imagine them so I can remember them more easily.
Because I learned a lot more about the interworkings of DNA, I understand chromosomes, cells, and organisms a lot more now, and going back and reviewing those topics will be a lot easier.
I want to learn more about how mutation pushes evolution further and faster.


https://upload.wikimedia.org/wikipedia/commons/0/07/Gene.png

https://upload.wikimedia.org/wikipedia/commons/thumb/2/22/Lac_Operon.svg/2000px-Lac_Operon.svg.png

Friday, December 4, 2015

DNA Extraction Lab

In this lab, we asked ourselves, "how can DNA be separated from cheek cells in order to study it?" We were able to find DNA from cheek cells by first breaking down the cell membranes and nuclear material of the cheek cell sample. We did this by homogenizing the cell tissue with polar liquid. We then facilitated the precipitation by shielding the negative phosphate ends of the DNA by adding salt. We then added soap to lyse the cell membranes and to emulsify the proteins and lipids of the cell. To further break down cell membranes and other nuclear material, catabolic proteases were added. We saw the DNA floating around in the test tubes, showing that the process had worked to find DNA. One error was that we put in a couple more drops of pineapple juice, or our catabolic proteases. This could have hurt our data because the cell membrane AND the DNA could have both been broken down. Another error was that we might have put in too much salt because the direction called for "a pinch of salt", which is not an exact measurement, leaving lots of room for error. This could have affected our data because the solution could have been over facilitated, allowing the negative phosphates of the DNA too close together. Being more careful would solve the first problem, and more specific instructions would have solved the second one. The purpose of this lab was to grasp a better understanding of DNA and its surroundings. This lab relates to where DNA is in the cell, which is something we learned in class. This lab would come in handy when looking for genetic disorders or for curious parents to see what a new child might possibly look like.




https://ge.unl.edu/journey-of-a-gene/knowledge/flash-cards/