General Features of Fatty Acid Structure The elements of fatty acid structure are quite simple. There are two essential features: 1. A long hydrocarbon chain OThe chain length ranges from 4 to 30 carbons; 12-24 is most common O The chain is typically linear, and usually contains an even number of carbons 2. A carboxylic acid group HHHH H HH HHHHHHHHHH O H-C-C-C-C-C-C-C-C-C-C-C-C-C-C-C-C-C-C HHHHHHHHHHHHHHHHH OH long hydrocarbon chain carboxylic id group Essential features of a fatty acid The many fatty acids which occur naturally arise primarily through variation of chain length and degree of saturation
General Features of Fatty Acid Structure The elements of fatty acid structure are quite simple. There are two essential features: 1. A long hydrocarbon chain ●The chain length ranges from 4 to 30 carbons; 12-24 is most common. ● The chain is typically linear, and usually contains an even number of carbons. 2. A carboxylic acid group The many fatty acids which occur naturally arise primarily through variation of chain length and degree of saturation
Carbon-Carbon double bonds Carbon-carbon double bonds(unsaturations) are found in naturally occurring fatty acids. There may be one double bond or many, up to six in important fatty acids. Fatty acids with one double bond are the most prevalent in the human body, comprising about half of the total Fatty acids with two or more double bonds occur in lesser quantities, but are extremely important. When double bonds occur they are almost always cis. If there is more than double bond, they occur at three-carbon intervals, e.g ,-C=C-C-C=C- This is called the div inylmethane pattern -C=C-C-C=C Double bond pattern of polyunsaturated fatty acids, the divinylmethane pattern Divinyl methane pattern, showing the cis-configuration Double bond patterns in polyunsaturated fatty acids
Carbon-Carbon Double Bonds Carbon-carbon double bonds (unsaturations) are found in naturally occurring fatty acids. There may be one double bond or many, up to six in important fatty acids. Fatty acids with one double bond are the most prevalent in the human body, comprising about half of the total. Fatty acids with two or more double bonds occur in lesser quantities, but are extremely important. When double bonds occur they are almost always cis. If there is more than double bond, they occur at three-carbon intervals, e.g., -C=C-C-C=C-. This is called the divinylmethane pattern
Classification of Fatty Acids One system of fatty acid classification is based on the number of double bonds 0 double bonds: saturated fatty acids HHHHHHHHHHHHHHHHH0 H-C-C-C-C-C-C-C-C-C-C-C-C-C-C-C-C-C-C H HHHHHHHH H HHH H Stearic acid, a saturated fatty acid double bond: monounsaturated fatty acids HHHHHHH0 文C-C-C-C-C-C-C-C-C HHHHH
Classification of Fatty Acids One system of fatty acid classification is based on the number of double bonds. ● 0 double bonds: saturated fatty acids ●1 double bond: monounsaturated fatty acids