H O 



H— C-OH + HO— C— (CH2)icCH3 



O 



H— C— OH + HO— C— (CHo)ioCH3 



O 

 II 

 H— C— OH + HO— C— (CHo)icCHo 



H 



H O 



H— C— O— C— (CHOieCHo + HoO 



O 

 II 

 ■H— C— O— C— (CH2)i6CH3 + HoO 



O 



H— C— O— C— (CH.)icCH3 + HoO 

 H 



Most natural fats are mixed triglycerides in which different fatty acids 

 are attached to the glycerol molecule. The general formula for a mixed 

 triglyceride containing the three different fatty acids, Ri, Ro, and R3, is 



O 



II 

 HoC— O— C— Ri 



1 o 



I II 



HC— O— C— Ro 



I O 



I II 



HoC— O— C— R, 



Carbohydrates 

 Carbohydrates are chain carbon compounds, the simplest of which 

 are the monosaccharides. Depending on the number of carbons in the 

 chain, the monosaccharides are designated as trioses (glycer aldehyde), 

 tetroses (erythrose), pentoses (ribose, deoxyribose), hexoses (glucose, 

 fructose), and heptoses (sedoheptulose). The structural configurations 

 of some of these sugars are shown in Formula (2-8). Low molecular 



CHO CHO CHO CHO CHoOH 



H.C.OH 



H.C.OH 



H.C.OH 



H.C.OH 



C=0 



CHoOH H.C.OH 



GLYCERALDEHYDE I 



CHoOH 



ERYTHROSE 



H.C.OH HO.C.H HO.C.H 



I I I 



H.C.OH H.C.OH H.C.OH (2-8) 



H.C.OH H.C.OH 



CHoOH 



RIBOSE 



CHoOH H.C.OH 

 '^^^""^^ CH2OH 



SEDOHEPTULOSE 



GENERAL MORPHOLOGY AND CHEMISTRY OF THE CELL / 21 



