Exercises in practical physiological chemistry

Paperback | February 3, 2012

bySydney William Cole

not yet rated|write a review
This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1904. Excerpt: ... CHAPTER I. THE PROTEIDS. A.. The colour reactions of Proteids. For the following reactions use egg-white that has been well beaten with six times its volume of water, or serum that has been diluted ten times with water. 1. The Xanthoproteic reaction. To 5 c.c. of the proteid solution in a test tube add about one-third of its volume of strong nitric acid. A white precipitate is formed. Boil for a minute. The precipitate turns yellow and partly dissolves to give a yellow solution. Cool under the tap and add strong ammonia till the reaction is alkaline. The yellow colour is turned to orange. Notes 1.--The essential features of the reaction are that a yellow colour is obtained when the solution is boiled with strong nitric acid, and that this yellow colour is intensified on the subsequent addition of ammonia. The white precipitate with nitric acid is not obtained with certain proteids (see ex. 12). 2. The reaction is given by all aromatic substances, such as benzoic acid (C6H6. COOH); phenol (C6H5. OH); salicylic acid (C6H,r ), etc. V COOH' 3. The aromatic substances in the proteid molecule that are responsible for the reaction are chiefly tyrosin and tryptophane. 2. Millon's reaction. Treat 5 c.c. of the proteid solution with half its volume of Millon's reagent. A white precipitate is formed. Boil the mixture. The precipitate turns to a brick-red colour, or disappears and leaves a red solution. Notes 1.--The essential of the reaction is the red colour on boiling. A white precipitate in the cold is given with urea, sulphates, etc. 2. The reagent is obtained by dissolving mercury in nitric acid and diluting with water. It contains mercurous and mercuric nitrates, excess of nitric acid, and a small amount of nitrous acid. 3. The reaction should never be attemp...

Pricing and Purchase Info

$19.95

Out of stock online

From the Publisher

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1904. Excerpt: ... CHAPTER I. THE PROTEIDS. A.. The colour reactions of Proteids. For the following reactions use egg-white that has been well be...

Format:PaperbackDimensions:34 pages, 9.69 × 7.44 × 0.07 inPublished:February 3, 2012Publisher:General Books LLCLanguage:English

The following ISBNs are associated with this title:

ISBN - 10:0217313949

ISBN - 13:9780217313940

Look for similar items by category:

Customer Reviews of Exercises in practical physiological chemistry

Reviews