146 



HEMOGLOBIN 



Firstly, as has already been stated, if all three constants are deter- 

 mined for the same solution, good agreement is found between the 

 ratio of the velocity constants and the equiUbrium constant. 



Secondly, altered hydrogen-ion concentration, in a certain region, 

 viz. between 5-6 and 9, would be expected to produce a profound 

 change in the equiUbrium, because whilst having almost no effect 

 on the oxidation, it greatly faciUtates the reduction. The greater the 

 hydrogen-ion concentration, the less oxygen will be taken up at a 

 given pressure. 



30 



1-5 



20 



10 



^ / 



10 



<« 



•O0S7 



30 60 -0033 -0035 



Fig. 46, A. Fig. 46, B. 



A. Abscissa = value of reduction velocity constant. Ordinate = temperature in 



degrees Centigrade. 



B. Abscissa = reciprocal of absolute temperature. Ordinate = logarithm of reduc- 



tion velocity constant. 



Thirdly, a rise of temperature should tend also to reduce the 

 quantity of oxygen taken up at a given oxygen pressure; for the 

 same reason, namely, that whilst the reaction 



Hb -f O2 — ^ HbOg 



has a temperature coefficient of approximately 1, that of the reaction 



HbOa — ^- Hb -f O2 



