Wednesday, September 29, 2010

Notes on Molelecular Structure

I thought I'd just go ahead and post my notes from today. Since these are notes, taken during class, these are disjointed and not exactly a masterpiece of the English language.



Shape matters in biochemistry! Simple structure changes have profound effects on the chemical properties of a molecule.

Monosaccharides often do not stay "mono." They bond together and become disaccharides--for example, glucose and fructose become sucrose. Double glucose is maltose, and glucose and galactose become lactose. (Lactose-intolerance is caused by lack of an enzyme that breaks the glucose and galactose bonds.)

Then, there are polysaccharides. "Simple" sugars (monosaccharides) are combined many times (a condensation reaction--water is released). For example, many glucose molecules are combined to create amylose. Amlopeclin is very similar to amylose, but has extra branches. These are considered starches.

Glucose can be combined (through condensation reactions) to create glycogen. This chemical is found in human cells, particularly muscle and liver tissue. Cellulose is when the glucose chains are "flipped." Between these chains, hydrogen bonds can be found. Because of this, these can be used to create structural support (such as a cell wall in plant cells).

Cellulose cannot be broken down (for the same reason that causes lactose-intolerance--the lack of an enzyme that can do so.)

Bugs are crunchy for the same reason--their exoskeleton is formed from chitin, which provides support because of the hydrogen bonds.

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