1889-90.] Dr G. E. C. Wood on Enzyme Action. 
33 
ingly, be regarded as specific in their nature, depending on the 
specific nature of the protoplasm of which they are merely further 
differentiations. 
The question now arises, Are the products originating from the 
action of different enzymes the same 1 We know, already, that the 
sugars and peptones, in certain cases, are different, and more exact 
investigation, coupled with more delicate methods, will, without 
doubt, in the future, add greatly to the number of these. We 
should not, then, regard the peptonisation as merely a breaking down 
of the complex proteid molecule into smaller, more diffusible mole- 
cules, which are in this way more easily absorbed. It is also a 
disintegration into simpler bodies of probably a quite definite com- 
position, which the protoplasm can either convert into colloid 
catalysable material to be stored up in the organism, or build 
up into its own proper substance. The protoplasm of bacteria has 
been shown to exhibit the greatest possible difference towards 
bodies all but indistinguishable from a chemical point of view. We 
possess indeed in these organisms one of the most delicate reagents 
at our disposal in differentiating organic bodies of allied constitu- 
tion. Thus, to take one example out of many, it has been found 
that the natural and artificially prepared inulins are treated as dis- 
tinct bodies by a microbe, the first being assimilated, the latter being 
left absolutely untouched. It is probable, then, that the process of 
peptonisation, in which the proteid molecule is, as it were, taken to 
pieces, is not always the same, but varies according to the specific 
nature of the protoplasm, in which it may have, afterwards, to 
undergo a process of building up to form an integral part. 
The enzymes have not yet been isolated as chemically pure bodies ; 
indeed, there is good reason to believe that, in most cases, these 
would be found to consist of several bodies corresponding to different 
stages of their action. This has been indicated most clearly in 
the case of the diastatic ferment obtained from malt.* The 
starch, after undergoing a first change into a soluble form, is con- 
verted into a molecule of maltose and dextrine; the latter then 
undergoes successive hydrations, until 52 per cent, of the maltose 
which the starch could have yielded, has been formed, at which stage 
the action of the ferment ceases. If, however, the ferment had been 
* Annales de VInstitut Pasteur , 1887. 
VOL. XVII. 18/2/90 
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