H2C=O-C一R HOC-OH RCOOH HC-0-C-R' (1)OH/H,O, heat HC-OH RCOOH (2)H3O H2C-O-C-R H2C-OH RCOOH A fat or oil Glycerol Fatty acids (油或脂) (丙三醇) (脂肪酸) Most of fatty acids have unbrached chains and they have an even number of carbon atoms The double bonds in unsaturated fatty acids are all cis and not conjugated. Many naturally occurring fatty acids contain two or three double bonds. Triple bond rarely occur in fatty acids Saturated fatty acids have relatively high points and unsaturated fatty acids have relatively low pointsH2 C HC H2 C O C R O C R' O C R'' O O O A fat or oil (油或脂） H2 C HC H2 C OH OH OH + RCOOH R'COOH R''COOH (1) OH- / H2 O, heat (2) H3O + Glycerol ( 丙三醇) Fatty acids (脂肪酸） Most of fatty acids have unbrached chains and they have an even number of carbon atoms. The double bonds in unsaturated fatty acids are all cis and not conjugated. Many naturally occurring fatty acids contain two or three double bonds. Triple bond rarely occur in fatty acids. Saturated fatty acids have relatively high points and unsaturated fatty acids have relatively low points