118 



PROTEINS 



COOH 

 I 



COOH 

 I 



H,N-C— H HjN— C— H 



COOH 

 I 



COOH 

 I 



I 

 CHj 



S — 



-CH, 



I 

 CHj 



I 



H,N— C— H HjN— C— H 



L-Djencolic acid 



v» 



CHj 

 I 

 CHr 



CH, 



-A- 



(Horiiocysteine part) (Cysteine part) 

 L-Cystatliionine 



COOH 

 I 

 H— C— NH2 

 I 

 H3C — C — CH3 



SH 



D-Penicillamine 

 OS-thiolvaline) 



D. Adds containing iodine. 



COOH 



I 

 H2N-C— H 



CH2 

 I 



HC^ ^CH 



I II 



IC^^^CI 



I 

 OH 



L-Diiodotyrosine 



COOH 

 I 

 H2N— C— H 



CH2 

 1 



HC^ ^CH 



I II 



IC^^^CI 



I 







I 



HC^ ^CH 



I II 



I 

 OH 



L- Thyroxine 



