Previously, we talked about the difference between organic (based on carbon) and inorganic (based on some other element) molecules. Life, of course, is based on organic molecules. There are four major classes of carbon-based compounds used by living things: carbohydrates, lipids, proteins and nucleic acids. Each of these compounds is made of individual 'building blocks' called MONOMERS. The monomers are linked together with covalent bonds to make large chains called POLYMERS, and the process of making polymers is referred to as POLYMERIZATION.
Here's a video from Bozeman Science, with animations, that gives some nice background on monomers and polymers:
Carbohydrates are carbon-based macromolecules based on C, H and O. They are polar and readily dissolve in water. A simple sugar by itself, like glucose, is termed a monosaccharide, and serves as a 'building block' (monomer) to build a larger chain of many molecules called a polymer. In the case of carbohydrates, the polymer made from many monosaccharides linked together by dehydration reactions is called a polysaccharide. Examples of polysaccharides made of glucose include cellulose, glycogen and starch. Each of these glucose polymers are biologically important.
Finally, here's yet another video by AP Chemistry teacher Paul Andersen, this on the class of macromolecules called PROTEINS.
PROTEINS often are used to build extremely useful and specific molecules called ENZYMES:
In this handy video, Paul Anderson reviews the basic rules for ionic and covalent bonding. Students should compare this video with their 'Nomenclature Review' handout, as well as the (ionic) version of the periodic table on the back of their Unit 8 syllabus.
Mr.Hatfield's Chemistry students have completed their Notes on material from Chapter 19. They can download a copy of the Power Point containing those Notes HERE:
Students received a Study Guide based upon this section of Notes in Friday's class, to help prepare for their Unit 7 test on Wednesday, April 3rd.
Tyler DeWitt has made a very handy, easy-to-understand video that uses the formation of an ionic compound (NaCl, sodium chloride) to illustrate the logic of oxidation-reduction reactions, sometimes called 'redox' reactions, as described in Chapter 20.
Tyler not only gives an example of oxidation numbers (20.2), but he also shows how to to use these numbers to describe 'half-reactions' (20.3) While there is no worksheet based upon this video, this is highly-similar to how students will be introduced to these concepts in Lecture, and is worth repeated viewings:
Students were shown this video in Friday's class. Paul Andersen demonstrates the centrality of water to most acid-base chemistry, and explains how to calculate equilibrium constants for acids (Ka) and bases (Kb), and how to express those as pKa's or pKb's:
