Proteids

Noncrystallizable bodies composed of carbon, hydrogen, oxygen, and nitrogen, found in all animal fluids and in nearly all of the tissues.

They include albumins, fibrin, globulins, etcetera.

Protein

An artificial albuminoid, once erroneously supposed to be the base of all proteids.

Albumin

A group of proteids soluble in water. Coagulate by boiling and with acids.

Ammonia

A colorless, pungent, strongly alkaline gas existing free in air and soil. A product of putrefaction of all organisms. Found in a minute quantity in air.

Nitrogen

A colorless, tasteless, inodorous gas. Incombustible, not a supporter of combustion. Exists in atmosphere and forms about four-fifths of it by bulk.

Carbohydrates

Compounds of carbon with hydrogen and oxygen, the two latter in the proportions that form water. Include sugar, starch, cellulose, gum, and dextrin.

Starch

A vegetable principle, white, tasteless, inodorous, insoluble in cold water. Dilute acids and diastase convert it into dextrin and dextrose.

Glucose

Grape sugar, dextrose, starch sugar. Found in grapes and other fruit. Commercially prepared from starch by the action of very dilute sulphuric acid. Less sweet than cane sugar.

Diastase

A nitrogenous principle developed in grain during germination and causes conversion of starch into dextrin and dextrin into glucose.

Dextrin

A substance isomeric with starch, from which it is derived by the action of heat, acids, diastase, etc. When dry it has the physical properties of gum arabic and is used for it.

Dextrose

A term applied to glucose. Rotates polarized light to the right.

Levulose

Fruit sugar, honey sugar. Rotates polarized light to the left.

Ptyalin

A hydrolytic ferment found in saliva.

Hydrocarbons

A compound containing hydrogen and carbon only.

Fats

Soft solid fixed oils of vegetable or animal origin.

Protoplasm

An essential to the phenomena of life, common to all organisms. A semitranslucent, semiliquid, viscous substance without visible structure, irritable, contractile, and metabolic or changeable. Probably the ultimate element.

Assimilation

The taking into and making part of the organism.

Metabolism

Tissue change in nutrition and secretion. Includes anabolism and catabolism.

Anabolism

A building-up process of forming living protaplasm from dead nutrient material.

Catabolism

A process of forming products of secretion by protoplasm. Retrograde metamorphosis.

Sarkin

A leucomaine, and appears as a ptomaine in albuminous substances containing nuclein.

Xanthin

An amorphous extractive occupying an intermediate place between sarkin and uric acid in the decomposition of muscle.

Enzyme

A chemical ferment, as in the digestive juices. It does not depend on micro-organisms for its action.

Nucleus

That part of the protoplasm of a cell which contains chromatin and may or may not be separated from the protoplasm by a membrane.

Chromatin

A substance of the nucleus having affinity for coloring matter. Possibly identical with Nuclein.

Karyoplasm

A protoplasm of the nucleus.

Leucocyte

A colorless cell-like mass of protoplasm, the lymph-corpuscles and white corpuscles of the blood, having amoeboid movements, but usually spherical in form.

Leucomaine

An animal alkaloid akin to a ptomaine, developed in the body during life.

Bile

Secretion of the liver.

Pancreatin

A pancreatic ferment which emulsifies fats and converts starch into sugar.

Pepsin

A nitrogenous enzyme of the gastric juice.

Calorie

A unit of heat, being the amount required to warm one gramme of water one degree Centigrade. The dynamical equivalent of one calorie is forty-two million ergs.

Erg

A unit of work, being the work done in pushing one gramme of mass through one centimetre of space against a force of one dyne. It is also a unit of energy, since energy is measured by work.

Dyne

A unit representing the force which, acting for one second on a mass of one gramme, gives it a velocity of one centimetre per second.