The egg white is a clear liquid (also called albumen or ovalbumin) contained within a bird's egg. It is the cytoplasm of the egg, which until fertilization is a single cell. It consists mainly of about 10% proteins dissolved in water. Its primary purpose is to protect the egg yolk and also to provide additional nutrition for the growth of the embryonic chick, as it is rich in proteins and is of high nutritional value. Unlike the egg yolk, it contains little fat. Orders Many - see section below. ... An average Whooping Crane egg is 102 mm long, and weighs 208 grams A baby tortoise emerges from a reptile egg. ... Cytoplasm is the viscid, semi-fluid matter contained within the plasma membrane of a cell that helps to hold the cell together. ... Categories: Biology stubs ... Cells in culture, stained for keratin (red) and DNA (green) The cell is the structural and functional unit of all living organisms. ... A representation of the 3D structure of myoglobin, showing coloured alpha helices. ... The egg yolk is the yellow inside an egg. ...

It is often used and separated for cooking (for glairs, meringues, soufflés, and some omelettes), which is where it derives its name from: when egg white is beaten it turns white. For the Dominican or Haitian folk dance and the music it is performed to, see merengue. ... An Omelette or omelet is a preparation of beaten egg cooked with butter or oil in a frying pan, often folded around a filling. ...

In schools it is often used to teach pupils how to test for protein using Biurets reagent.

Composition

The main constituent of egg white is a protein termed ovalbumin, which is structurally a serpin (a class of proteins), although it does not have a known function in inhibiting other proteins. Serine protease inhibitors or serpins (short for serine protease inhibitor) are a group of proteins that inhibit peptidases (old name: proteases). ...

Denaturation

All proteins, including those in egg white, are made of long chains of amino acids which might be considered as like beads on a string. In a raw egg, these strings are ravelled up in a tangled compact mass. There are bonds between the amino acids within each protein that stop the ball from unravelling. As the egg cooks the heat causes the bonds within the proteins to break. Each ball of protein unfolds and tangles up with the other protein balls. Bonds form between the amino acids on different proteins setting the albumen into a rubbery gel. When boiling eggs in water, some people add salt to the water for no good reason [1]  (http://www.princeton.edu/~lehmann/BadChemistry.html#Solutions). In chemistry, an amino acid is any molecule that contains both amino and carboxylic acid functional groups. ... Sodium chloride, also known as common salt, table salt, or halite, is a chemical compound with formula NaCl. ...

What happens to an egg white as it is beaten

The protein partially unravels and forms a good foaming agent. A foam is formed by the protein forming a stable film around the included air. Studies show that the best foam forms when the unraveling of the protein is only partial. Overbeating egg white destabilises the foam by completely unravelling the protein molecules. The protein is elastic, so when the egg white is cooked, and the air expands, the white stretches then sets in the expanded position. The most general definition of foam is a substance that is formed by trapping many gas bubbles in a liquid or solid. ...

Use of a copper bowl

Many cooks recommend using a copper bowl to beat egg white. This has the effect of making it take longer to form the foam, but leads to a much more stable foam. This probably because the copper atoms form a complex with the conalbumin protein which makes it difficult to unravel, which means that it takes around twice the time to get a good foam, but very much more difficult to overbeat. (The danger of overbeating may be the reason many cooks recommend beating by hand rather than use an electric whisk) General Name, Symbol, Number copper, Cu, 29 Chemical series transition metals Group, Period, Block 11 , 4, d Density, Hardness 8920 kg/m3, 3. ...

The one possible drawback of using a copper bowl is the toxicity of copper. However, the amount incorporated into the white is likely to be far too small to cause ill effect. For a list of biologically injurious substances, including toxins and other materials, as well as their effects, see poison. ...

Cream of Tartar

Cream of tartar (potassium bitartrate) is an acidic salt can be used to change the pH of the egg white to an acidic range of around 3-4. This has the effect of stabilising the foam, and is therefore a good alternative to using a copper bowl. Cream of tartar should not be used if a copper bowl is used, because it can react with the copper and force more of it into solution (acids react with metals, in general), thus increasing the toxic effect. Cream of tartar is the potassium salt of tartaric acid, KHC4H4O6. ... An acid (often represented by the generic formula AH) is typically a water-soluble, sour-tasting chemical compound. ... PH or ph or pH or Ph may be: In chemistry, pH is a measure of acidity. ...