Introduction to physiological chemistry / by Meyer Bodansky.

  • Meyer Bodansky
Date:
[1930]
Catalogue details

Licence: Public Domain Mark

Credit: Introduction to physiological chemistry / by Meyer Bodansky. Source: Wellcome Collection.

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    of fundamental chemical principles, as he must learn to apply these principles to physiological processes. He also requires technique in quantitative chemical analysis. Equipped with these tools, he may proceed to study the composition of tissues, the chemical constitution of foodstuffs, the fate of these in digestion and metabolism, the data of animal calorimetry, and similar problems. It should always be borne in mind, however, that in the nature of things he will be limited in cer- tain respects. A tissue subjected to chemical manipulation is no longer a living tissue; the process of analysis frequently involves its destruc- tion. One of the student’s tasks, therefore, is to learn to correlate analytical data with function. As biochemists, we are especially inter- ested in the numerous changes or reactions that occur in every living cell of the living organism. Scope.—What, then, is to be the scope of our subject? It should obviously include a consideration of the composition and chemical properties of protoplasm. Protoplasm is the main constituent of the living cell, whether plant or animal, and is regarded by most biologists as the physical basis of life. In appearance it is slimy or jelly-like; its main constituents are present in finely divided aggregates or in a state of emulsion. Being a heterogeneous mixture, protoplasm exhibits the properties of substances in the colloidal state. Physico-chemical methods of study and physico-chemical concepts have therefore been most useful in contributing to our meager understanding of the prop- erties and behavior of protoplasm. We shall consider in this chapter, in a preliminary way, certain of the constituents that are found in living tissues. This will afford us a knowledge of what the body requires for the purposes of growth and maintenance, and will serve as an introduction to the study of the three main classes of foodstuffs—the carbohydrates, fats, and proteins. The chemical processes that render the food we eat assimilable are included under the head of digestion. In the chapter devoted to this topic, the progress of the foodstuffs in the alimentary tract will be followed, and a study will be made of the changes that take place under the influence of the saliva, the gastric juice, and the secretions of the pancreas and small intestine. The mechanism whereby the products of digestion pass through the intestinal wall into the blood and lymph will then be discussed. After absorption, the food material is carried to the tissues where it is used either for tissue formation or for energy production. The higher animals possess a very elaborate transport system, the blood and lymph. This system is also concerned with the transportation of oxygen to the tissues and of carbon dioxide from them.
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