The white of a raw egg is clear It contains the protein albumin When cooked changes from to opaque producing What happening at molecular l?

When a raw egg white is heated, the protein albumin undergoes a process called denaturation. This means that the structure of the protein is changed, causing it to become opaque and firm.

The denaturation of albumin is caused by the breaking of hydrogen bonds and disulfide bonds within the protein molecule. These bonds hold the protein in its native shape, and when they are broken, the protein unfolds and becomes more flexible.

The unfolded protein molecules then aggregate together, forming a network that traps water molecules. This network is what gives cooked egg whites their characteristic opaque appearance and firm texture.

The temperature at which albumin denatures depends on the pH of the solution. In a neutral solution, albumin denatures at around 68°C (155°F). However, the denaturation temperature can be lowered by either increasing or decreasing the pH.

For example, albumin denatures at a lower temperature in an acidic solution than in a neutral solution. This is because the hydrogen ions in an acidic solution weaken the hydrogen bonds within the protein molecule, making it more susceptible to denaturation.

Conversely, albumin denatures at a higher temperature in a basic solution than in a neutral solution. This is because the hydroxide ions in a basic solution strengthen the hydrogen bonds within the protein molecule, making it more resistant to denaturation.

The denaturation of albumin is an important process in cooking. It is what causes egg whites to set, custards to thicken, and meringues to form.