AP BIOLOGY

Detailed explanation-1: -In a fatty acid chain, if there are only single bonds between neighboring carbons in the hydrocarbon chain, the fatty acid is said to be saturated. Saturated fatty acids are saturated with hydrogen since single bonds increase the number of hydrogens on each carbon.

Detailed explanation-2: -Saturated chains contain all single bonds, while the unsaturated ones have one (monounsaturated) or more (polyunsaturated) double bonds. The number of hydrogen atoms in the formula of an unsaturated structure will be less than that for the corresponding saturated one with the same number of carbon atoms.

Detailed explanation-3: -The simplest fatty acids are unbranched, linear chains of CH2 groups linked by carbon-carbon single bonds with one terminal carboxylic acid group. The term saturated indicates that the maximum possible number of hydrogen atoms are bonded to each carbon in the molecule.

Detailed explanation-4: -Saturation/Unsaturation Carbon normally has four bonds to it. Thus, a saturated fatty acid has hydrogens at every position except carbon-carbon single bonds and carbon-oxygen bonds on the acid end. Two examples of the same 18 carbon saturated fatty acid (stearic acid/stearate) are shown in Figures 2.321 and 2.323.