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Unit 3: Lesson 2-Fundamentals of Organic Chemistry

Terms in this set (77)

-called fats or triglycerides
-contain an alcohol called glycerol, and a group of compounds known as fatty acids
-glycerol molecules- have 3 C atoms- to which are attached 3 OH groups
-Fatty acids- consist of long hydrocarbon chains, ending in a carboxyl (-COOH, organic acid) group.
-most common fatty acids contain an even number of C atoms
-molecule of fat- formed when 1 glycerol molecule combines with 1-3 fatty acid molecules.
-# of fatty acid molecules- determines if it's a monoglyceride, diglyceride, or triglyceride
-in the reaction, 1-3 molecules of H2O are formed (dehydration), depending on the # of fatty acid molecules reacting.
-chemical bond formed where H2O molecule is removed is called an ester linkage
-in hydrolysis (reverse reaction)- fat molecule is broken down into fatty acid and glycerol molecules
-wide variety of lipids - b/c fatty acids that form lipids have diff. structures (see Fig 2.9c)

-primary function of lipids: -to form plasma membranes that enclose the cell
-plasma membrane- supports the cell; allows nutrients and wastes to pass through
-lipids must maintain the same viscosity regardless of surrounding temp.
-must be as viscous as olive oil (without getting too fluid when warmed or too thick wen cooled)
-animal fats- solid at room temp; vegetable oils- liquid at room temp.
-difference in their melting points is due to degree of saturation of fatty acid chains
-Fatty acid is saturated- when it has no double bonds- the carbon skeleton contains the maximum number of H atoms. (see Fig. 2.9c and Fig 2.10a)
-saturated chains- become solid more easily b/c they are mostly straight and are able to pack together more closely than unsaturated chains.
-unsaturated chains- double bonds create kinks in the chain, keeping the chains apart from one another (fig 2.10b)
-2.9c- H atoms on either side of the double bond in oleic acid are on the same side of the unsaturated fatty acid.--- called a cis fatty acid
-if the H atoms are on the opposite sides of a double bond, the unsaturated acid is called a trans fatty acid