Glucose

“ To use a homely figure of comparison, the energy-producing substances of the human body—glucose, glycogen, and fat—may be compared to the movement of [205] merchandise in ordinary commerce. We could say that the glucose of the blood is as merchandise in the hands of the people, ready to be consumed. The glycogen of the liver would represent goods in the hands of the retailer, while the fat which is stored in larger quantities would be represented by merchandise in warehouses. ”

“ They are abundant in the blood during the hours following meal-taking, and diminish in fasting. The sugar glucose, for instance, is present in blood taken early in the morning in a concentration of about one part in each thousand, or 0.1 per cent, but when carbohydrates are being digested, one and one-half parts of glucose in each thousand, or 0.15 per cent are found. ”

“ There are some persons, perhaps, who do not realize that beside cane sugar many kinds of carbohydrate occur in our food. Glucose or grape sugar, for example, occurs not only in the fruit indicated by its name, but also in other fruits, in corn, in onions, and in the common vegetables. Glucose is especially suited to act as nourishing food. ”

“ As in the case of soft sugars, the lighter the molasses is in color, the more agreeable is the flavor of the confections made from it.
13. GLUCOSE.--Another substance much used in the making of confections is glucose. It is usually manufactured from the starch of corn and is put on the market under various trade names, but generally it is called corn sirup. Many persons have long considered glucose a harmful food, but this belief has been proved untrue. Glucose has come to be absolutely necessary in some candy making in order to produce certain results. ”

“ Of Glucoses the best example is dextrose = C6H12O6, H2O, which can be seen crystallised in dried raisins; it only possesses one-third the sweetening power of sucrose. Starchy food becomes changed into glucose by the action of saliva and pancreatic juice in the alimentary canal. ”

“ Test: Add yeast to the urine and keep at 15° to 20° C. when if glucose is present, it becomes cloudy and gives off carbon dioxide, or add a little caustic potash solution, and a few drops of cupric sulphate solution until it is blue: then heat and a red precipitate of cupreous oxide is thrown down. The amount gives the ratio of glucose. Uric acid, hypoxanthin or mucus causes brown precipitate in the absence of glucose: peptone, creatin, creatinine, pepsine and urinary pigment prevent its formation though glucose be present. ”

“ The power of storing and using sugar in the tissues is strictly limited, and varies considerably in healthy individuals. Normally, when about 200 grms. of glucose are taken at one time, some of it appears in the urine within one hour. In some individuals the taking of even 100 grms. leads to a transient glycosuria, while others can take 250 grms. or more and use it all. But even in the same healthy individual the power of using sugar varies at different times and in different conditions, muscular exercise markedly increasing the combustion. ”

“ If glucose is used in proper proportions, it makes an excellent lowering agent, and will answer the purpose first rate for ordinary drops and the like. Use three lbs. of glucose to every 14 lbs. of sugar; keep a panful on the furnace top, so that it will always be hot and may be easily measured by means of a saucepan or ladle holding the exact quantity; add the glucose when sugar begins to boil. ”

“ Diabetes Mellitus.—The quantity of urine is very large. The color is generally pale, while the specific gravity is nearly always high—1.030 to 1.050, very rarely below 1.020. The presence of glucose is the essential feature of the disease. The amount of glucose is often very great, sometimes exceeding 8 per cent., while the total elimination may exceed 500 gm. in twenty-four hours. It may be absent temporarily. Acetone is generally present in advanced cases. Diacetic acid may be present, and usually warrants an unfavorable prognosis. ”

“ When a surplus amount of carbohydrate food is eaten, over and above the immediate needs of the body for fuel, it is stored in the liver and muscles as glycogen, which can be readily reconverted into glucose. When the supply of carbohydrate food is greatly in excess of the body’s needs, that is when the liver and muscles cease to store glycogen, it is built up into adipose tissue and furnishes a readily available source of emergency fuel. ”

“ We know that one of the principal functions of the liver is to maintain at a constant level the quantity of glucose held by the blood, by means of the reserves of glycogen secreted by the hepatic cells. Now, in this circulation of glucose and accumulation of glycogen, it is easy to see that the effect is as if the whole effort of the organism were directed towards providing with potential energy the elements of both the muscular and the nervous tissues. ”

“ Glucose (often called also dextrose, fruit sugar, or grape sugar) occurs widely distributed in plants, most commonly in the juices of ripening fruits, where it is usually associated with fructose and sucrose, the two hexoses being easily derived from sucrose by hydrolysis. Glucose is also produced by the hydrolysis of many of the more complex carbohydrates, by the action either of enzymes or of dilute acids; lactose, maltose, raffinose, starch, and cellulose, as well as many glucosides all yielding glucose as one of the products of their hydrolysis. ”

“ In The Popular Science Monthly for June, 1881, appeared an article on Glucose and Grape-Sugar, by Prof. H. W. Wiley. In that article the following unfortunate statement was made: "In commercial honey, which is entirely free from bee mediation, the comb is made of paraffin, and filled with pure glucose by appropriate machinery." To say that there was not one word of truth in that extraordinary assertion is the short and proper way to put it, and that is exactly what I undertake to say. ”

“ Commercial Glucose.—The glucose of commerce, which may be regarded as a mixture of grape sugar, maltose and dextrins, is prepared by hydrolysing starch by boiling with a dilute mineral acid. In Europe, potato starch is generally employed; in America, corn starch. The acid employed may be hydrochloric, which gives the best results, or sulphuric, which is used in Germany; sulphuric acid is more readily separated from the product than hydrochloric, since the addition of powdered chalk precipitates it as calcium sulphate, which may be removed by a filter press. ”

“ Commercial glucose, as was explained in Lesson IV, is made by treating starch with dilute acids, and its wholesomeness depends entirely upon the care with which this is done. Theoretically, glucose is a very good food. In practise it is somewhat risky because cheap chemicals used in its manufacture may leave harmful and poisonous substances in the finished product. ”

“ The principal carbohydrates are starch, dextrine, cane-sugar or common table sugar, grape-sugar, the principal sugar in fruits, and milk-sugar, the natural sugar in milk. They are substances made up, as before stated, of carbon, hydrogen, and oxygen, but no nitrogen. They are important food substances, but are of themselves incapable of sustaining life.
The carbohydrates, both starch and sugar, in the process of digestion are converted into glucose. This is stored in the liver in the form of glycogen, which the liver has the power of manufacturing ”

“ Levulose, lactose, and some others are occasionally met with.
(1) Glucose (Dextrose) .—It is probable that traces of glucose, too small to respond to the ordinary tests, are present in the urine in health. Its presence in appreciable amount constitutes "glycosuria."
Transitory glycosuria is unimportant, and may occur in many conditions, as after general anesthesia and [p. 77] administration of certain drugs, in pregnancy, and following shock and head injuries. ”

“ The use of glucose, not only in beer, but as an admixture or adulterant in jams, syrups, candies, and the like, is open to serious objection unless the glucose is known to have been prepared with sulphuric acid freed from arsenical impurity. ”

“ A sort of wine of very agreeable taste is made from the fruit juice. Lately the powdered seed has been recommended in the treatment of glycosuria or at least it has been stated that its internal use lessens and finally abolishes the glucose from the urine of the patient. It has even been affirmed that while under this treatment the patient may eat glucose-forming foods without fear of glycosuria supervening. ”

“ When, for example, the flow of bile is lessened, an incomplete emulsification of the fats exists and the fatty acids which are highly acid in character cannot be efficiently dissolved or neutralized, or when the liver is diseased and for this reason the conversion of glycogen into glucose is interfered with, the utilization of the carbohydrate foods is thus impaired. ”

“ In addition to the pancreatic juice and bile there is a secretion known as intestinal juice which is poured out by small glands scattered along the wall of the small intestine. These secrete enzymes which convert the various kinds of sugar into the particular sugar, glucose, which is the one the body can use. The glands also secrete an enzyme which can carry on to completion protein digestion. Thus there is ample insurance that all the foodstuffs shall be made ready for the use of the body. ”

“ After the food has been masticated and saturated with saliva, it passes down the throat through the gullet, which performs a peculiar muscular contraction, thrusting downward the particles of food. The conversion of the starch in food into sugar, or glucose, which is begun by the saliva in the mouth, is continued as the food passes into and down the gullet, but stops almost completely when the food once reaches the stomach. ”

“ What is sold in enormous quantities to the people as sugar, whether alone or as part of preserves, turns out often to be glucose. Butter, so-called, is often only skilfully-treated fats, the weight helped out by water. These three articles of diet alone, when adulterated as they thus often are, mean serious deterioration in the food—and therefore in the physique—of the nation ”

“ Very few people know how glucose is made and are under the impression that it is an injurious adulteration. Because glucose is used extensively in cheap candy, there is a certain amount of prejudice against it. ”

“ Glucose is the active saccharine principle in maize, but it does not become active until the corn is treated chemically in a certain way, just as honey is not honey until a bee puts it through his Maeterlinck laboratory.
Glucose is a food ”

“ Bees eat glucose with the greatest avidity, or, rather, they act as funnels by which the glucose is poured into the comb. For it is quite true that honey made by bees which have free access to glucose differs scarcely at all from the glucose itself. But the quantity of honey which a bee will store away when fed on glucose is truly wonderful. ”

“ Sugar, Diabet′ic. Grape sugar found in the urine of persons labouring under diabetes. In diabetes insipidus, a substance having the general properties of a sugar, but destitute of a sweet taste, appears to be produced (Thénard.)
Sugar, Gel′atin. See Glycocine.
Sugar, Grape, C6H12O6.H2O. Syn. Glucose, Fruit sugar; Saccharum uvæ, S. fructus, L. This substance is found in the juice of grapes and other fruit, in the urine of diabetic patients, and in the liquid formed by acting on starch and woody fibre with dilute sulphuric acid. ”

“ Sugar, on the other hand, is a perfectly soluble or "meltable" substance, and can soak or penetrate through any membrane or substance in the body. Therefore all the starches which we eat—bread, biscuit, potato, etc.—have to be acted upon by the ferments of our saliva and our pancreatic juice, and turned into sugar, called glucose, which can be easily poured into the blood and carried wherever it is needed, all over the body. Thus we see what a close relation there is between starch and sugar, and why the group we are studying is sometimes called the starch-sugars. ”

“ Tube, and sterilise as for bouillon.
Ordinary commercial glucose serves the purpose equally well, but is not recommended, as during the process of sterilisation it causes the medium to gradually deepen in colour.
Note.—In certain cases a corresponding percentage of lactose, maltose, or saccharose is substituted for glucose.
Sugar Gelatine.—
1. Prepare nutrient gelatine (vide page 164, sections 1 to 7) . Measure out 1000 c.c.
2. Weigh out glucose, 20 grammes (= 2 per cent.) , and dissolve in the hot gelatine. [Pg 185]
3. Filter through papier Chardin. ”

“ The package contained ampules of thin, fragile, brown colored glass, containing approximately 21⁄2 c.c. of light, clear, amber colored, thick, sticky fluid, having a distinct caramel odor. Reaction pH = 5.0. A reducing substance (probably glucose) amounting to 7.4 per cent. was found by using Benedict’s method for estimating glucose quantitatively; after hydrolysis with hydrochloric acid, 55.5 per cent. glucose was found. ”

“ We flit through the dreamy hours of summer like swift-winged bumble bees amid the honeysuckle and pumpkin blossoms, storing away, perhaps, a little glucose honey and buckwheat pancakes for the future, but all at once, like a newspaper thief in the night, the king of frost and ripe mellow chilblains is upon us, and we crouch beneath the wintry blast and hump our spinal column up into the crisp air like a Texas steer that has thoughtlessly swallowed a raw cactus.
Life is one continued round of alternative joys and sorrows. ”