298 Biological Chemistry. 



u + H 2 = 2C 6 H 12 8 



It has been found by Croft Hill that when a concen- 

 trated aqueous solution of glucose is treated with this 

 enzyme, the reverse reaction takes place, namely 



C 6 H 12 6 + C 6 H 12 O fl = H a O + CuHaO,! 



The actual disaccharide isolated in this case was found to 

 be a mixture of the isomerides maltose and isomaltose, 

 and this fact gave rise to the discussion as to whether 

 the enzyme which produces synthesis is identical with that 

 causing hydrolysis. The bulk of the evidence seems to 

 indicate, however, that the synthetic and hydrolytic actions 

 are due to the same enzyme, and the seemingly anomalous 

 result obtained by Croft Hill is explained by the fact that 

 maltase sometimes contains the two enzymes, namely, true 

 maltase and emulsin (compare p. 295). 



Another well-established synthetical reaction of en- 

 zymes is that of the lipase, which can be prepared from 

 castor-oil seeds and chelidonium seeds. Under certain 

 conditions these enzymes can produce the synthesis of 

 fats from a mixture of glycerol and the higher fatty 

 acids, and an equilibrium point can be attained with a 

 relatively large amount of fat. The reaction may be 

 shortly represented by the equation 



CH 2 -0-OCR CH 2 -OH 



CH-O-OCR' + 3H 2 ^= CH OH + R-CO-OH + R'-CO OH 



CH 2 .0-OCR" CH 2 -OH +R"-CO OH 



It has recently been shown that whether the reaction is 

 started with a mixture of a fat and water, or of fatty acids 

 and glycerol, the same final equilibrium point is attained. 



The general characters of the enzymes may be sum- 

 marized in the following manner ; 



