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Ebook Organic chemistry principles in context: Part 2

(BQ) Part 1 book "Organic chemistry principles in context" has contents: Fatty acid catabolism and the chemistry of the carbonyl group; investigating the properties of addition and condensation polymers; the industrial road toward increasing efficiency in the synthesis of hexamethylene diamine with stopovers at kinetic versus thermodynamic control of chemical reactions, nucleophilic substitution, and with a side trip to laboratory reducing agents,.and other contents. | Chapter 7 Fatty Acid Catabolism and the Chemistry of the Carbonyl Group 7.1 The fatty acids in living organisms are saturated and unsaturated. T HE “FATS OF LIFE” BY CAROLINE POND is full of interesting information about its subject matter including a story I remember reading years ago in a popular textbook of organic chemistry written by two professors at New York University, which is that the hoofs of reindeer contain a higher proportion of unsaturated fatty acids than the upper body areas of this animal. There are many different kinds of fatty acids, some of which are shown in Figure 7.1. These molecules, with variable length long hydrocarbon chains terminated by carboxylic acid groups, can be broken down into two classes, saturated and unsaturated. In fatty acids these terms take on special importance. FIGURE 7.1 Structures and Melting Points of Various Saturated and Unsaturated Fatty Acids In biological systems unsaturated refers to those molecules that contain one or more carbon-carbon multiple bonds (section 4.10, Figure 4.12), which refers in the most part to sp2 carbon atom hybridized carbon-carbon double bonds in long chains made up mostly of sp3 hybridized carbon atoms (section 1.4, Figure 1.2). We have hardly noted triple bonds in our studies, that is, sp hybridized carbon, and triple bonds, although not unknown, are rarely found in natural fatty acids, so, for now, we can restrict our definition of unsaturated fatty acids to those containing carbon-carbon double bonds, which, as we shall see, are essential in the role fatty acids play in living systems. Caroline Pond, in her book, points out that the shingle-backed lizard, which lives in the deserts of western Australia, when fed a diet of unsaturated fatty acids likes to spend its time in cooler places compared to being fed a diet of saturated fatty acids after which it likes to hang around in warmer places. Other lizards apparently behave in a similar manner. That’s pretty interesting. As in .