Parts of an Egg and their Functions - Science

An egg has several parts, each with specific functions. The shell is the outer protective layer, keeping the egg safe from bacteria and damage, made mostly of calcium. Inside, the shell membrane lies just under the shell, providing another layer of protection and helping to control moisture loss. The air cell forms at the larger end of the egg due to air permeating through the shell as the egg ages. The egg white, or albumen, surrounds the yolk and is mainly water and protein, offering cushioning and nutrition, while also fighting bacteria with its antimicrobial properties. The yolk is the central, nutrient-rich part, containing fats, vitamins, and minerals, which nourish the developing embryo if the egg is fertilized. The chalazae are two cord-like structures that anchor the yolk in the center of the egg white, maintaining its position. Lastly, the vitelline membrane encloses the yolk, keeping it separate from the white and protecting it from bacterial invasion.