. Chemical embryology. Embryology. 1030 CARBOHYDRATE METABOLISM [PT. Ill. Fig. 282. carbohydrate. The former falls to a level of about 100 and subsequently rises to over 300, the latter rises all the time in an S-shaped curve to about 48 mgm. This would seem to indicate that the carbohydrate present in the embryo on the 4th and 5th days, at which time there is more in proportion than at any subsequent period, is not in the form of free glu- cose, and as it cannot be glyco- gen it must be sugar in some unidentified combined form. The dry weight data bear out this view even better. On the 5th da
. Chemical embryology. Embryology. 1030 CARBOHYDRATE METABOLISM [PT. Ill. Fig. 282. carbohydrate. The former falls to a level of about 100 and subsequently rises to over 300, the latter rises all the time in an S-shaped curve to about 48 mgm. This would seem to indicate that the carbohydrate present in the embryo on the 4th and 5th days, at which time there is more in proportion than at any subsequent period, is not in the form of free glu- cose, and as it cannot be glyco- gen it must be sugar in some unidentified combined form. The dry weight data bear out this view even better. On the 5th day 100 gm. of dry embryo contain 3000 mgm. of total carbohydrate, about 100 mgm. of free carbohydrate, and about the same amount of glycogen. After that point the total carbohydrate continuously falls, reaching a value of 1750 on the i6th day, while the free carbohydrate continuously rises, its highest point being reached on the 11 th day with a ^''°°° value of 360 mgm., after which i it falls, but not below 220 mgm. e^°°° The fact that the total glucose | falls, while the free glucose "5,2000 rises, is of some interest. The 2 presence of such a large pro- 0,000 portion of glucose not free and 5 ^ not in the form of glycogen a may be correlated with certain histological facts which have been known for some time, and which have already been referred to (see p. 566). What happens to the concentration of the various carbohydrate fractions in the water of the embryonic body? It was pointed out above that when total protein, total carbohydrate and total fat were expressed as grams per 100 gm. of water in the embryonic body, the protein and the fat start at a very low level (owing to the great wetness of the earhest stages) and rise steadily, while the carbo- hydrate begins fairly high, falls to a minimum on the 8th day, and. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance
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Keywords: ., bookcentury1900, bookpublishernewyorkthem, booksubjectembryology
