410 



Dr. A. Compton. The Influence of the Hydrogen 



Table I. 



Quantities of acid and alkali added per 

 5 cm. 3 of the reaction mixture. 



Maltose hydrolysed. 



25 cm. 3 M/100 H,S0 4 



0-15 „ „ 



o-io „ „ 



0-05 „ „ 



- 00 „ (natural reaction ; control) 

 0-05 „ M/100 NasCOa 



o-io „ „ 



Per cent. 

 28 -2 

 63 5 



75 -1 



76 -8 

 34 -3 

 14 -2 



3 2 



When the percentage of maltose hydrolysed' is plotted against the 

 quantities of reagents added, the curve indicated in fig. 1 is obtained. 



Eg. 1. 



M/j 



100 H 2 SO /I 



tyiooNa'CO 3 



0-6 0-5 0-4- 0-3 0-2 Ol O Ol 



. CKt 5 per 5CM- 3 reaction mbcture. 



\o-20 017 013 oio 007 003 o 003 



l CM 3 per MGRM. of enzyme approoc. 



-30 -3-3 -3-2 -34 -4-7 -56 -62 -7Z -75 



lO XO lO lO lO lO — lO lO XO — 



H concentration of inedium. 



007^ 



This curve shows that under the conditions of the experiment the addi- 

 tion of the merest trace of alkali is detrimental to the enzyme action ; while 

 on the contrary the addition of acid increases the efficiency of the enzyme, 

 until a certain point is reached, corresponding to the presence of - 07 cm. 3 

 M/100 H 2 S0 4 in the 5 cm. 3 reaction mixture, beyond which the addition of 

 more acid is in turn detrimental to the action. In other words, the action 

 passes by a maximum situated in the acid region. 



