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In biochemistry, denaturation is a process in which proteins or nucleic acids lose folded structure present in their native state due to various factors, including application of some external stress or compound, such as a strong acid or base, a concentrated inorganic salt, an organic solvent (e.g., alcohol or chloroform), agitation and radiation, or heat. [3]
Ovalbumin is a storage protein in egg white (albumen). It is a serpin. Lactalbumin, or whey protein, is a protein fraction of milk. It is mainly Beta-lactoglobulin, although serum albumin also comprises a small part of it. Some plant seeds, including hemp, encode "2S albumins". These are named for their egg-like coagulation property. [11]
Egg white consists primarily of about 90% water into which about 10% proteins (including albumins, mucoproteins, and globulins) are dissolved. Unlike the yolk, which is high in lipids (fats), egg white contains almost no fat, and carbohydrate content is less than 1%. Egg whites contain about 56% of the protein in the egg.
Heller's test is a chemical test that shows that strong acids cause the denaturation of precipitated proteins. Concentrated nitric acid is added to a protein solution from the side of the test tube to form two layers.
Ovalbumin (abbreviated OVA [1]) is the main protein found in egg white, making up approximately 55% of the total protein. [2] Ovalbumin displays sequence and three-dimensional homology to the serpin superfamily, but unlike most serpins it is not a serine protease inhibitor. [3]
A raw egg yolk surrounded by the egg white. Avidin was first isolated from raw chicken egg white by Esmond Emerson Snell. Avidin was discovered by Esmond Emerson Snell (1914–2003). This discovery began with the observation that chicks on a diet of raw egg white were deficient in biotin, despite availability of the vitamin in their diet. [8]
Egg white albumen is composed of multiple proteins, of which ovotransferrin is the most heat reliable. It has a molecular weight of 76,000 daltons and contains about 700 amino acids . Ovotransferrin makes up approximately 13% of egg albumen (in contrast to ovalbumin , which comprises 54%). [ 2 ]
The process of cooking an egg causes the proteins within the yolk and albumin to denature and solidify, resulting in a solid egg white and yolk. [5] Coagulation (denaturing) of egg white proteins begins in the 55–60 °C (131–140 °F) temperature range, and egg yolks thicken at the slightly higher temperature of 65 °C (149 °F), solidifying ...