256 



UNITY AND DIVERSITY IN BIOCHEMISTRY 



H2N 



\^~ 



CH2— O — PO(OH)2 

 ^C glycine 



H H 



H2C — NH2 



I 



^0 = C — NH — R— 5' — O — P0(0H)2 



C — C 



H I I H 

 OH OH 



5 '-phosphoribosylamine 



H2C 



NH 



\ 

 CHO 



glutamine 



ATP 



glycinamidoribotide 



H2C — NH 



\ 

 CHO 



HN = C— NH— R— 5'— O— P0(0H)2 



formylglycinamidinoribotide 



HC — N 



= C— NH— R— 5'— O— PO(OH)2 



formylglycinamidoribotide 



\ 



aspartate, CO2 H2N — C = O 



CH 



ATP 



•N 



H2N — C — N — R — 5' — O — PO(OH)2 

 aminoimidazoleribotide 



\ 

 CH 



H2N— C— N— R— 5'— O— PO(OH)2 

 aminoimidazolcarboxamide ribotide 



xanthosine 

 monophosphate 



+ H0O — 2H 



HN — C = O 



HC 



C — N 



adenosine 

 ' monophosphate 



aspartate 



glutamine or NH3 



\- 



CH 



guanosme 

 monophosphate 



N — C — N — R — 5' — O — PO(OH)2 



inosine monophosphate 



Fig. 74. 



