Essay on Biochem Task 2

(a) Describe THREE types of chemical bonds/interactions found in proteins. For each type, describe its role in determining protein structure.

Proteinaceous Infectious Particles, commonly known as Prions, are extremely rare misfolds of the protein PrPc, which cause fatally neurodegenerative diseases, and are theorized to be infectious only by the protein itself (U.S National Library of Medicine, 1998). This “protein-only theory” is still heavily debated today, as some scientists deny the theory, and there isn’t a significant amount of evidence on each side to qualify the theory or disprove it (Soto, C. 2011). The base “Prion” protein is encoded in the gene PRNP, while being non-infectious. Prions are most commonly found in human prion diseases, but they can also be in other animals in the form of Mad Cow Disease and Chronic Wasting Disease, classified as Bovine Spongiform Encephalopathies

3. Suppose you are performing an experiment in which you must use heat to denature a double helix and create two single stranded pieces. Based on what you know about nucleotide bonding, do you think

Box on right illustrates the peptide bond resulting from the condensation of both the amino acids. The box on the left illustrates the separation of the hydroxide group from glycine and the hydrogen atom from valine.

For the peptide Ala-Arg-Lys-Ala-Asn-Ser-Ala-Ser, what would be the expected charges at pH 1, 7, and 13?

Course description: The chemistry and biological properties of amino acids, proteins, nucleic acids, lipids, carbohydrates, and vitamins. The course includes laboratory and tutorial sessions.

Proteins are polymeric chains that are built from monomers called amino acids. All structural and functional properties of proteins derive from the chemical properties of the polypeptide chain. There are four levels of protein structural organization: primary, secondary, tertiary, and quaternary. Primary structure is defined as the linear sequence of amino acids in a polypeptide chain. The secondary structure refers to certain regular geometric figures of the chain. Tertiary structure results from long-range contacts within the chain. The quaternary structure is the organization of protein subunits, or two or more independent polypeptide chains.

Neurodegeneration occurs from the shrinkage of the brain, specifically the gray and white matter. Gray matter in the brain is comprised of cell bodies, dendrites, and axon terminals of neurons,

A prion is a pathogen that lacks nucleic acid. Though they cannot reproduce and are not susceptible to procedures that break down the nucleic acid, they can replicate by stimulating normal cellular prion protein to refold from normal prion protein to abnormal prion protein. They replicate in neural tissue causing degeneration and death. The actual process of how normal prions convert to abnormal prions remains unknown.

Creutzfeldt-Jakob Disease is a rare neurodegenerative disorder that is caused by a unique infectious agent called prion. It is neither a virus or bacteria and is not even a living organism but purely a protein that infects the brain causing neuro-degradation and eventually death. CJD is the human disorder from a family of prion diseases which have also been found in animals such as sheep called Scrapie Disease, cattle known as Bovine Spongiform Encephalitis, and deer named Chronic Wasting Disease (Anderson, Salm, Allen, 2016, p.356). Researchers found that this prion disease is caused by a misfolding of a normal prion-related protein, PrPc. These normal proteins are genetically synthesized proteins normally found on surfaces of neurons. While there are still uncertainties about the functions of these normal PrPc proteins, there is some evidence that it is

It has been considered to be one of the most mysterious diseases scientists are fighting so far. With no effective treatment or research on the disease, it has a 100% fatality rate, however fortunately for us, the disease is extremely rare with only 2 cases and deaths since 2008. The disease is caused by an abnormal and infectious protein in the brain called a prion. Normally, prions are used to help transmit messages between certain brain cells. They use “protein folding” which is beginning as a string of amino acids and folding themselves into a 3-D shape. However, CJD causes mistakes in the process, which causes misfolded prion proteins to spread, whereas a healthy person’s body easily recycles them. As more and more misfolded prion

Causes for Creutzfeldt-Jakob disease involve abnormal infectious protein in the brain called prion. Proteins are molecules that help the cells in the body to function. These proteins fold into a 3-Dimensional shape (protein folding) that enables them to perform useful functions inside cells in the body. Prions are misfolded prion proteins that begin to build up in the brain causing others to misfold as well. This process causes brain cells to die which then release more prions to other cells of the brain. Over time, the process kills numerous brain cells and deposits of prions, known as plaques, appear in the brain. Prion infections cause small holes to appear in the brain, the damage leads to the mental and physical impairment caused by CJD

Transmissible spongiform encephalopathies (TSEs) are neurodegenerative diseases that are thought to be caused by the misfolding of prion proteins. Prions are able to replicate in the absence of nucleic acids. TSEs include: scrapie, bovine spongiform encephalopathy, Creutzfeldt-Jakob disease, kuru, Gerstmann-Straussler-Scheinker disease, and Fatal Familial Insomnia. They can affect many different animals, including humans. Currently, there are no ways to diagnose, treat, or cure TSEs, as much more research is needed before these diseases are completely understood.

Campbell and Farrell define proteins as polymers of amino acids that have been covalently joined through peptide bonds to form amino acid chains (61). A short amino acid chain comprising of thirty amino acids forms a peptide, and a longer chain of amino acids forms a polypeptide or a protein. Each of the amino acids making up a protein, has a fundamental design that comprises of a central carbon or alpha carbon that is bonded to a hydrogen element, an amino grouping, a carboxyl grouping, and a unique side chain or the R-group (Campbell and Farrell 61).

These new formations are held together by hydrogen bonds. The third level is the tertiary structure. The tertiary structure of a protein is a contorted secondary structure being twisted and folded all out of shape to form a 3-d complex. The type of bonding that holds these formations together are weak interactions such as hydrophilic, hydrophobic, ionic, and hydrogen bonds. These bonds are individually weak, but collectively strong. The forth level, which completes a protein, is quaternary structure, which occurs when two or more tertiary structures are joined together by polypeptide bonds.