H 



HC 

 H 



I 



NHj 



NHe 



r 



I 



HC 



I 

 HC-OH 



I 

 HC-OH 



I 

 HC 



I 



N 



I 



HCa, 



HC — — P- 

 H II 







0" 



I 



-P- 



II CH 



^C-N^ 



I 

 HC 



I 

 HC-OPOsH- 



I 

 HC-OH 



I 

 HC 



I 



NHe 



I 



N C — N, 



I II 



N I 



HC- 

 I 



CH 



HC-OH 



I 

 HC-OH 



I 

 HC 



-CH 

 H 



I 



0" 



I 



0' 



I 



Triphosphopyridine nucleotide (oxidized form) 

 (TPN+) 



"-C-" 



HC — O — P-0-P-O-P-OH 

 H II II II 







Adenosine triphoiphote (ATP) 



In Adenosine diphosphote (AOP), 

 terminal phosphate is replaced by -OH. 



HC 

 II 

 HC> 



II 

 ,CH 



N 

 I 

 R 



'NHg 



NIcotinomide portion of 

 TPNH (reduced TPN+) 



Figure 1. Formulas of TPN and ATP. 



DPNH are reducing agents and carriers of chemical poten- 

 tial, in other words, strong reducing agents. Thus, one of 

 their roles in biochemistry is analogous to that of H2 in syn- 

 thetic organic chemistry. 



The function of ATP is to carry chemical potential and 

 to act as a powerful phosphorylating agent. In the reduction 

 of an acid to an aldehyde, important in photosynthesis, its 

 role may be compared to that of a mineral acid anhydride 

 in organic synthesis: 



Organic synthesis: 



Car- Acid 



boxylic anhy- 



acid dride 



O 



/ 

 (3) R— C + iPCI, 



OH 



Aldehyde 



// 



O 



Acid 



R— C -f HCl 



H 



