244 Triacylglycerols(三脂酰甘油)are unhydrated and thus much lighter than saccharides, which are highly hydrated( e.g., one gram of dry glycogen binds two grams of waterl 2.4.5 Warm-blooded polar animals are amply padded with triacylglycerols as insulation against very low temperatures
2.4.4 Triacylglycerols（三脂酰甘油） are unhydrated and thus much lighter than saccharides, which are highly hydrated (e.g., one gram of dry glycogen binds two grams of water!). 2.4.5 Warm-blooded polar animals are amply padded with triacylglycerols as insulation against very low temperatures
Some Naturally Occurring Fatty Acids Ability at 30C Common name Structure 120 CHaICH-J1oCOOH n Dodecanoic acid Lauric acid ( Latin Laurus laurel plant") CHaICH-1COOH Myristic acid 5390.024874 nutmeg genus) CH,ICH, ),COOH Hexadecanoic acid Palmitic acid 0.0083 8 (Latin palma palm tree”) 180 CHaICH2)1 COOH n-Cctadecanoic acid 6960.0034124 (Greek stear 20:0 CHaICH2LeCOOH n-Eicosanoic acid Arachidic acid 76.5 legume genus 24:0 CHa(CH2) COoH Tetracosanoic acid Lignoceric acid 86.0 (Latin Lignum wood"+cera, wax) 16:1(4) CH, (CH,);CH=CH(CH2)COOH cis-9-Hexadecenoic acid Palmitoleic acid 0.5 18:14" CHa(CH)CH=CH(CH2)COOH cis-9-Octadecenoic acid ole ic acid 13.4 (Latin oleum 18: 2(4) CH, (,)4CH=CHCH, CH= cis, cis-9. 12-0ctadecadienoic Linoleic acid CH(CH,)_COOH Greek linon,“ax”) 18:3(A2)CH,CH_CH-CHCH,CH- cs,s,cs9,12,15 CHCH CH=CH(CH3),COOH Octadecatrienoic acid 20: 4(4B. 4)CHa ICH2)4CH-CHCH-CH- cis, cis-, cis, cis-5. 8, 11, 14. Arachidonic acid -495 CHCH CH-CHCH CH Eicosatetraenoic acid CH(CH):COOH All acids are shown in their nonionized form. At pH 7, all free fatty acids have an ionized carboxylate. Note that numbering of carbon atoms begins at the carboxyl carbon configuration of each double bond is indicated: in biological fatty acids the configuration is almost alwas cf ted fatty acids, e"ould The prefix n indicates the"normal "unbranched structure. For instance, dodecanoic"simply indicates 12 carbon atoms, which co be arranged in a variety of branched forms: "r-dodecanoic"specifies the linear, unbranched form. For unsatur
Stearic acid oleic acid or oileate Carboxyl oO group C H ydrocarbon chain (b)
Stearic acid Oleic acid or Oileate
Saturated Mixture of saturated and fatty acids unsaturated fatty acids (c) (d)
CHe CH HO OH OH CH, CH,O 1-Stearoyl, 2-linoleoyl, 3-palmitoyl glycerol, a mixed triacylglycerol