Lipids

Relatively large biological molecule that mostly does not dissolve in water.Lipids include fats, oils, cholesterol, a number of steroid hormones, the major constituents of cell membranes, etc.Lipids are predominantly hydrophobic substances, though can have hydrophilic portions as well. An example of the latter are lipids associated with membranes, that is, lipid bilayers, include phospholipids and the molecule, cholesterol.Unlike proteins, carbohydrates, and nucleic acids, lipids are less homogenous in terms of their structures. In particular, lipids do not have a consistent subunit from which they are polymerized but instead are categorized together as a group based upon their relative inability to dissolve in aqueous solutions. That is, they are oil-like in the generic sense of that term. The video placed a whole new spin on the age of rap and showed that is just not for young persons.Furthermore, while being enjoyable it also teaches one about lipids in a fun interactive session.

Reference

“Michael Eskin Lipids Rap,” Youtube Video, 2:52,posted by”Lipids Get a Real Bad Rap: It’s Just Not Fair,” May 17,2012, http://www.youtube.com/watch?v=6lrG65DdBl8

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Shampoos and Conditioners

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Perming, relaxing, and coloring are the harshest things you can do to your hair from a chemist’s viewpoint. But shampoos and conditioners also take advantage of chemistry to get their work done.┬áThe job of shampoo is to clean the hair, so it’s not surprising that the main ingredient in nearly all shampoos is detergent. Detergents create an anionic, or negatively charged, solution when combined with water. Such a formula is good for cleaning hair by attracting positively charged ions, such as oil. But it also tends to ruffle hair’s outer cuticle, explaining why just-washed hair is often flyaway, unmanageable, and rather dull.To counteract these undesirable effects and smooth down the hair cuticle, people often follow a shampoo with a rinse of a cationic, or positively charged, solution. In years past, people used vinegar, lemon juice, or beer for this purpose. Such rinses made hair glossier and easier to comb, but they could leave hair smelling like a tossed salad or a brewery. Modern conditioners achieve the same results and also have a pleasant fragrance more appropriate for hair.One of the most important classes of conditioning agents is the quaternary ammonium compounds. These cationic substances help counteract static electricity and flyaway hair by binding to the anionic strands of shampooed hair. Because hair that has been permed, relaxed, or colored is considerably more anionic than normal hair, manufacturers design special conditioners packed with cationic ingredients for hair that has undergone a strong chemical treatment. Some formulas can even temporarily repair or strengthen chemically processed hair through the use of cationic proteins that cling to the hair’s weakened keratin chains through hydrogen bonds.

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referenced: Good Hair days: A Case of Good Chemistry.”Shampoos and Conditioners.” Accessed April 3rd, 2013.http://tlc.howstuffworks.com/style/a-case-of-good-chemistry-info5.htm