Friday, November 16, 2007

Protein's Cont'd

Hey guys, well I know the structure of proteins is kind of difficult to learn, but I will try to do the best I can to help you guys understand this.

The primary structure is basically the order of amino acids in chains. Even a slight change in the amino acid can affect a protein's structure and then FUNCTION. One protein can determine the difference between sickle cell anemia and the normal red blood cells.

The secondary structure is local folding. This folds along short sections of polypeptide. They are hydrogen bonds between each R groups.
The dotted lines between the diagram are hydrogen bonds.

The tertiary structure is also known as whole molecule folding. This is determined by interactions between R groups. Hydrophobic bonds want to stay away from water so they cluster together so that the hydrophobic bonds are next to each other, clustered together. This is important in the structure of the the cell membrane. The hydrophobic tails basically face each other in a cell membrane, away from the water and cluster together, while the heads are hydrophylic and face the water. This forms a phospholipid bilayer.

The quaternary structure is when more than one polypeptide chain is joined together. However, it is important to note that not all proteins have subunits and more than one polypeptide. This polypeptide take different shapes and this then determines their functions. Its basically HYDROPHOBIC INTERACTIONS.

The unfolding of a protein has a fancy name for it called denaturing. When a protein unfolds, the tertiary structure, or 3' structure is disrupted. The pH, otherwise the acidity, is one of the factors. Another is salty environment, as well as temperature. Size doesn't matter, shape matters. Denaturing of proteins disrupts the H bonds, ionic bonds, and disulfide bridges. Ms. Foglia had boiled milk and added vinegar. Vinegar is an acid which disrupting the shape of the proteins. And believe it or not, it is the process of making cheese!!!

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