A second linked reaction, mediated by a peroxidase, catalyses the reaction between the peroxide and a chromogen ( a substance that acquires colour after a chemical reaction ) to form a coloured compound that indicates the glucose concentration.
22.
In spite of the inquiry being only in its initial stages, there is already good evidence to believe that Cu�not's theory is correct, and that an albino is an individual whose skin lacks the power to secrete either the ferment or the chromogen.
23.
The urine test strip test for blood is based on hemoglobin s pseudo peroxidase activity in catalysing a reaction between hydrogen peroxide and the chromogen tetramethylbenzidine in order to produce a dark blue oxidation product . the resultant colour can vary between green and dark blue depending on the amount of hemoglobin.
24.
Not only do albinoes thus carry the determinants ( genes ) for pattern, but it has been known for some time that they also carry gametically, but never visible somatically, the determinants ( genes ) for either the ferment ( enzyme ) or the chromogen ( substrate ) for one or more colours.
25.
Subsequently ( 1903 ) L . Cu�not, in order to explain certain features in the hereditary transmission of coat colour in mice, postulated the hypothesis that the grey colour of the wild mouse ( which is known to be a compound of black, chocolate and yellow pigments ) may be due either to the interaction of a single ferment and three chromogens, or vice versa, to one chromogenic substance and three ferments .
