WGU C785 2 nd OA Dump File

2 nd OA Dump File UNIT 2: AMINO ACIDS, PEPTIDE BONDS, PROTEIN STRUCTURE  Remembering amino acids o Polar amino acids- Polar bears like water! Polar amino acids = OH, NH, SH or use S.O.N o Nonpolar amino acids- hydrophobic- CH “Can’t Have” water - Question w/ pics of amino acids where you pick out the non-polar (CH) amino acid Look for CH, CH2, CH3  these are weak interactions that tend to go in the middle of a protein (aggregation) and are affected by temperature change. o Ionized amino acids- the charged amino acids +/- attached to them. Neurodegenerative protein aggregation: Misfolding of a protein structure in Alzheimer’s Disease the most common neurodegenerative disease. The formation of the aggregated amyloid-beta fibers another characteristic of Alzheimer’s. The neurodegeneration and memory loss can be detected before the amyloid fibers accumulate in the brain. o Caused by intracellular tangles and extracellular plaques (senile plaques) caused by ABNORMAL PROTEIN AGGREGATION.  Chaperones- molecules that help denatured proteins in folding (they help newly formed proteins and can also help the misfolded ones) Know the levels of protein structure Primary= chain of amino acids, peptide bonds forming a polypeptide chain. Covalent bond= strong and does not denature - What structure would be unaffected by complete denaturation of multisubunit? Primary!!!! Peptide bonds are strong and covalent. Primary formed by peptide bonds Secondary= alpha helix and beta sheets, held together hydrogen bond, denatured by salt and pH change. Carboxyl grp and amino grp. secondary held together by hydrogen bonds. Hydrogen bonds formed from 2 polar amino acids!!! Which factor is most influential in the formation of a protein’s secondary structure? The formation of hydrogen bonds between amino acids Tertiary= 3-D shape (sickle cell, arthritis, hemophilia) Changes seen with ↑temp, salt, change in pH, and reducing agents. Tertiary structure is HYDROPHOBIC, found on inside, protein structure is stabilized primarily by the hydrophobic effect, disruption of the hydrophobic effect is the simplest way to denature—which is done by ↑temp from heating up. Quaternary subunit= more than one polypeptide, HgB Changes seen with ↑temp 1. Peptide bond- peptide bonds form between 2 amino acids via DEHYDRATION reaction. During the reaction, a water molecule (H20) forms from the oxygen of a carboxyl grp and 2 hydrogens from an amino grp. As water forms, the carbon atom of the carboxyl grp and the nitrogen atom of the amino grp become bonded together. This bond between the two amino acids is called a peptide bond. Which molecule is produced when two amino acids are joined by a peptide bond?