Record Details
Field | Value |
---|---|
Title | Contractions accompanying the swelling of gelatin in solutions of varying pH |
Names |
Brown, Betty
(creator) Friedman, Leo (advisor) |
Date Issued | 1934-05-24 (iso8601) |
Note | Graduation date: 1934 |
Abstract | There are two distinct methods which are used to study the volume changes which take place when a protein is placed in a solution. The first and most common method measures the volume changes of the solid alone and is commonly known as swelling. The second measures the total volume change which takes place upon mixing the two components--that is, the volume of the solution plus the volume of the solid protein minus the volume of the resulting system. The results of the first method have been thought to indicate the degree of water absorption, while the second supposedly indicates the degree of hydration. A knowledge of the latter might possibly lead to a better understanding of the processes of the former, and, consequently, to a better understanding of the phenomenon of swelling. Up to the present time, very few measurements have been made on the total volume changes occurring during the swelling of proteins, and the results which have been published do not substantiate each other. Therefore a study of the volume changes accompanying the swelling of gelatin in solutions of varying hydrogen ion concentration has been made in an attempt to correct and correlate the data already present in the literature. Measurements have been made to determine the influence of pH on the contractions accompanying the swelling of gelatin. It was found that a definite minimum in contraction occurred at the isoelectric point, the contraction increasing with increase or decrease in the hydrogen ion concentration. The maximum and minimum in the contraction curve below the isoelectric point occurs at a pH corresponding to the maximum and minimum in the swelIing curve given by Loeb. The maximum on the basic side is shifted toward the isoelectric point. No second minimum occurs at the higher pH values. The contraction-time curve has the same general shape as an absorption-velocity curve. When the contraction per gram of water imbibed is plotted against the time a straight line is obtained. The results indicate that the contraction per gram of the original gel is independent of the amount of gelatin used. |
Genre | Thesis/Dissertation |
Topic | Proteins |
Identifier | http://hdl.handle.net/1957/51720 |