Out of Stock
Overview
Purchase of this book includes free trial access to www.million-books.com where you can read more than a million books for free. This is an OCR edition with typos. Excerpt from book: CHAPTER II The Purification Of Enzymes For many purposes we can use, without further treatment, the extracts of the tissues containing ferments. The investigations of zymase by Buchner' and his collaborators were made with the press-juice of the yeast. Emil Fischer has studied the enzymes by hydrolyzing the disac- charides with the simple, unpurified extracts of yeasts and animal tissues. For the glycolytic enzymes in the tissues of the higher animals, no method is known to-day by which the enzymes may be purified without destroying them. Other enzymes withstand chemical treatment, and in many investigations it is necessary to remove proteins, nucleic acids, salts, carbohydrates, etc., accompanying the enzymes in the watery extract. Even the natural secreted juices are not pure solutions of enzymes. The saliva and the enteric juice contain sodium chloride and sodium carbonate; the pancreatic juice and the secretion of the liver of the cephalopods contain sodium carbonate and perhaps carbonates of organic bases; the gastric juice contains hydrochloric acid; and, in addition, all these juices contain proteins and nucleic acids, and perhaps also lecithins. The organism can secrete liquidswhich do not contain proteins or nucleic acids, e.g., urine, bile, sweat; or liquids which contain these bodies in traces, e.g., the aqueous humor, the cerebrospinal fluid, and some liquids in invertebrates, for instance echinodermata. But these secretions are free from enzymes. The secretions containing enzymes are rich in proteins and nucleic acids. The quantity of these in the gastric and pancreatic juice varies proportionately with the enzymes, and their solubility is like that of the enzymes. Therefore many authors have thought them to be the enzymes; but they are mistaken, because we can ...
| ISBN-13 | 9780217718349 |
|---|---|
| ISBN-10 | 0217718345 |
| Weight | 0.47 Pounds |
| Dimensions | 9.00 x 6.00 x 0.32 In |
| List Price | $14.14 |
| Format | Paperback |
|---|---|
| Pages | 136 pages |
| Publisher | |
| Published On | 2009-08-01 |
View All Offers
Sort by:
Price
