The new health guide / edited by Sir William Arbuthnot Lane.

  • Lane, William Arbuthnot, 1856-1943.
Date:
[1935]
Catalogue details

Licence: In copyright

Credit: The new health guide / edited by Sir William Arbuthnot Lane. Source: Wellcome Collection.

    45/226 (page 41)
    We thus visualize digestion as the slow passage of food along the alimentary canal, mixing in the various sections with the appropriate digestive secretions, which in the end convert the proteins into amino acids, the carbohydrates into dextrose, and emulsify and saponify the fats; these final products eventually reaching the blood-stream. ENZYMES The molecular changes which take place in the food principles are brought about by ferments termed enzymes. These ferments usually act on the indiffusible foods by duplication into smaller molecules with the assumption of water, the process being termed hydrolysis. The action is strictly limited by the acid or alkaline reaction of the media in which they are functioning and also by temperature. The human enzymes, for example, will only function properly at approximately the body temperature of ioo° F. The table on pages 42 and 43 gives the more im- portant human enzymes and their action on food. SUMMARY OF DIGESTION In the Mouth.—Food mechanically reduced and prepared for gastric digestion by mastication and part of the starch converted into dextrin and maltose. Proteins and fat not acted on, and sugars merely dissolved.