Search -
Directions for a Practical Course in Chemical Physiology
Directions for a Practical Course in Chemical Physiology Author:William Cramer 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: PARTIAL HYDROLYSIS OF STARCH BY ACIDS. PREPARATION OF DEXTRIN. Preparation of Experiment YJ.—Proceed as in Experiment 7, but add only ten drops of concent... more »rated hydrochloric acid to 100 c.c. of starch paste. Remove every three minutes about 5 c.c. of the solution, cool, and test with dilute iodine solution. Discontinue the boiling when a purple or red colour is obtained with iodine. The solution then contains erythrodextrin. To the remainder of the solution apply Trommer's, Fehling's, and Xylander's tests. Record your results. lysis of Starch. Preparation of Dextrin and Maltose by action of Saliva on Starch. Tests far Maltose. PARTIAL HYDROLYSIS OF STARCH BY FERMENTS. PREPARATION OF DEXTRIN AND MALTOSE. Experiment 18.— Prepare some dilute saliva by rinsing out the mouth for 1 minute with 5 c.c. warm water. Collect the washings in a beaker. Repeat. Filter the dilute saliva. Place a series of drops of iodine on a porcelain plate. Put some starch solution (about 5 c.c.) in a test tube and add about half a test tubeful of saliva. Shake the mixture and place in the water-bath at 40= C. Every minute take out a drop with a glass rod and apply it to one of the iodine drops on the porcelain slab. What changes take place in the mixture ? Keep the mixture in the water- bath for i to 1 hour, until all the starch has been transformed into maltose. This solution is used for Experiment 19. By what constituent of the saliva is starch transformed into maltose ? Experiment 19-—With the solution of maltose obtained in Experiment 18 carry out the tests 9 (K) to 14. Note the results. How does maltose differ from glucose, and how can it be distinguished from it ? LARD, OLIVE OIL. Solubility of Melt a little lard in a porcelain basin on a boiling water-bath ; wi...« less