8 



Pyruvic 



COOH 



I 



CO - 



I 



CH3 



COOH 



I 

 CH, 



I 

 CO 



I 



COOH 



THE :\IETABOLISM OF ALGAE 

 Acetic Citric 



•COa 



— >" 



COOH 



I 

 CH. 



CH.COOH 



II 



C(OH) 



I 

 COOH 



Oxaloacetic 



T2H 



COOH 



I 

 CH2 



I 

 CHOH 



COOH 

 k 



Malic 



±u,o 



COOH 



I 

 CH '- 



II 

 CH 



I 

 COOH 



Fumaric 



T2H 



COOH 



I -CO2 

 CH2 < 



I -aH 



CHo +H20 



I 

 COOH 



Succinic 



COOH 



TH,0 



CHo ^^=- 



C(OH)COOH 



I 

 CH2 



I 

 COOH 



Iso-citric 



COOH 



I 

 CO 



I 

 CH2 



I 



CH2 



I 



COOH 



TCO. 



Aconitic 



COOH 



CH 



II 

 C.COOH 



I 

 CH, 



I 

 COOH 



±HiO 



COOH 



I 

 CHOH 



I 

 CH.COOH 



i 



CH, 



I 

 COOH 



A 



T2H 



COOH 



I 

 CO 



I 



CH.COOH 



I 

 CH2 



I 

 COOH 



a-Ketoglutaric Oxalosuccinic 



FIG. 2. Scheme summarizing the reactions of the tricarboxylic acid 

 cycle (for further information see ref. 19). 



