Protein disease

In this project, we studied the process by which proteins are synthesized from DNA. Additionally, we researched genetic diseases and how they are caused by mutations. We started off by doing background research both individually through online resources.

We were assigned to make a presentation off how our disease works (by the way we got Alzheimer)

This is our presentation

Alzheimer's Aka, chronic forgetfulness

Core Concepts

Central Dogma — Protein Synthesis

Protein synthesis is the process by which DNA (stored in the nucleus) is utilized to build new proteins for cells. It consists of several steps; first, DNA is transcribed onto mRNA, then mRNA is translated into a real amino acid chain, and finally the amino acid chain is folded into a final protein. This process is known as the central dogma of biology since it is central to the understanding of how living things work.

Ribonucleic Acids

Ribonucleic acids are the "blueprints" of biology. There are two main types of these acids, RNA and DNA. DNA is composed of two deoxyribose sugar-phosphate "backbones" arranged in a double helical structure connected in the middle by perpendicular "rungs". These rungs are each made up of two nucleotides connected in the middle by a hydrogen bond. There are four possible nucleotides: Adenine, Thymine, Guanine and Cytosine. These nucleotides match in pairs; G↔C and A↔T always bond with each other, and no other combinations are valid.

RNA is much like DNA, except it has a single backbone with a single row of nucleotides instead of two. Additionally, instead of the nucleotide Thymine is replaced by Uracil for chemical reasons. RNA uses oxyribose, rather than deoxyribose, sugar in its backbone.

Transcription

Transcription occurs when DNA in the nucleus is copied onto blank mRNA. First, the DNA double helix is split in half by the enzyme helicase. Next, RNA polymerase moves down the chain (in a 5' → 3' direction) and places mRNA nucleotides that are complimentary to the strand. Complimentary bases are opposite to those on the DNA — so G → C, C → G, T → A, and A → U (U replaces T in RNA). The DNA is spliced together once more, and transcription of the new mRNA strand is complete.

Translation

The mRNA is now free to leave the nucleus (DNA never leaves since it would be too dangerous to corrupt the only blueprint the cell has). It enters a ribosome, a "protein factory", where the translation process now begins. Every 3 bases of the mRNA encode a single amino acid, and these are called codons. In the ribosome, a form of RNA called tRNA has matching anticodons (complimentary bases) for each codon, and these match together to determine which codon is which. On the opposite end of the tRNA is the corresponding amino acid for the codon it matches with. In this way, the tRNA lines up the correct amino acids based on the mRNA's genetic code.

As these amino acids line up, they form peptide bonds between them. This forms a polypeptide chain, a long chain of amino acids connected by these peptide bonds. This proto-protein leaves the ribosome and is now ready for folding.

Folding

The protein exits the ribosome and begins moving through the rough and smooth endoplasmic reticulums and the golgi body. The primary structure of the protein is its polypeptide chain structure. Formation of hydrogen bonds between the amino acids (and a few other chemical reactions) causes the chain to form its secondary structure, which is either an alpha-sheet or beta-helix. After this shape, the protein may be bent or twisted into a tertiary structure by polar action: hydrophobic and hydrophilic areas of the protein will be attracted to similar areas, pulling and pushing the structure.

Mutations

When something goes wrong in the process, the protein can become corrupted or damaged. There are many ways this can happen.

  • If a nucleotide is swapped around, the codon it is part of will be corrupted. This is a substitution and will result in a single amino acid being possibly changed in the final protein. Such a mutation is also known as a point mutation, which can either be silent (it changes to another codon that still encodes the same amino acid), nonsense (it changes to a STOP codon which will end the protein prematurely) or missense (it changes the resulting amino acid).

  • If a nucleotide is removed or added, a deletion or insertion (respectively), every codon afterwards will be corrupted as the entire sequence has been offset. This is called a frameshift mutation and is especially dangerous compared to a point mutation since it disrupts the entire protein.

Reflection

I personally think I didnt do the best on this project. I feel like I should have contributed more that I did and taken a bigger role than I did. I feel like I did good as a collaborator and critical thinker, I brought up many new ideas and expressed many solutions to the problems that we had. Somethings I with I could have worked on was conscientious learner. I didnt really work on the project outside of school, especially during break. I only worked on it in class with my group.