Task 2
Melissa Robinson
March 21, 2015
A1. Threonine is an essential amino acid that is classified as slightly polar due to its hydroxyl group and the ability to easily donate a hydrogen atom. This as well makes it hydrophilic and often will saturate the outer region of a water soluble protein. They hydroxyl side chain can undergo glycosylation by adding saccharides and phosphorylation by adding phosphate through the actions of threonine kinase (New World Encyclopedia, 2015).
B. Protein Structure
C. Peptide bond through dehydration
D. Peptide bond broken through hydrolysis
E. Four forces that stabilize tertiary protein structure The tertiary structure is the last shape formation that a protein undergoes and is determined by the various interactions that occur involving the variable R-group of each amino acid. This complex three-dimensional structure is stabilized by four forces: hydrogen bonding, hydrophobic bonding, ionic/hydrophilic bonding and disulfide bonding (Borges, 2014). Hydrogen bonds occur between polar, or charged amino acids. Hydrophobic bonds avoid water and occur between nonpolar amino acids. Due to their hydrophobic nature, these bonds often occur in the center of the structure and help pull it tightly together. Both the hydrogen and hydrophobic bonds are fairly weak, with hydrogen being the stronger of the two. Ionic bonds also known as hydrophilic bonds occur between the two opposite charged R-groups. The strongest of the four bonds is the disulfide bridge that literally holds the structure together. This bond is a covalent bond between two sulfur atoms that occurs only between two cysteine amino acids (Borges, 2014).
F. Bovine Spongiform Encephalopathy Prions are types of proteins that do not require nucleotides to reproduces. In 1997, Stanley Prusiner discovered prions and theorized that they existed in two forms: cellular (PrPc); and infectious (PrPSc), and that the two forms were exactly the same in
References: Borges, K. (2014). Protein Structure. Video. Retrieved from http://wgu.hosted.panopto.com/Panopto/Pages/Viewer.aspx?id=b8686074-1a41-428c-ab18-037fa5e070e3 Boundless. (2014). Boundless Biology: Protein Structure. Image. Retrieved on March 19, 2015 from https://www.boundless.com/biology/textbooks/boundless-biology-textbook/biological-macromolecules-3/proteins-56/protein-structure-304-11437 CDC. (2010). Centers for Disease Control and Prevention: BSE (Bovine Spongiform Encephalopathy, or Mad Cow Disease. Retrieved on March 19, 2015 from http://www.cdd.gov/ncidod/dvrd/bse/ Helmenstine, A. (n.d.). Mad Cow Disease: What You Need to Know About Bovine Spongiform Encephalopathy. Chemistry About.com. Retrieved on March 19, 2015 from http://chemistry.about.com/cs/howthingswork/a/aa122703a.htm New World Encyclopedia. (2015). Threonine. Retrieved on March 20, 2015 from http://www.newworldencyclopedia.org/entry/Threonine Purdue University Department of Chemistry. (n.d.). Image. Retrieved on March 20, 2015 from http://www.chempurdue.edu/gchelp/molecules/thr.gif Steade, R. (n.d.). Bioptics.co.uk: Hydrolysis of a dipeptide. Image. Retrieved on March 20, 2015 from http://www.biotopics.co.uk/as/dipeptidehydrolysis.html Thompson, J. (2014). Bovine spongiform encephalopathy. Video. Retrieved on March 19, 2015 from https://www.youtube.com/watch?v=TUDyxDQetB0 Wakefield, R. (2010). Peptide Bond. Image. Retrieved on March 18, 2015 from http://dtc.pima.edu/blc/1004thed/002/002_chem_models/molecule6proteins.html Wiley, J. et.al. (2002). Cutting Edge: Prions. Retrieved on March 19, 2015 from http://www.wiley.com/legacy/college/boyer/047003790/cutting_edge/prions/prions.htm