The structure of an egg consists of several key components. The outermost layer is the shell, which provides protection and is made primarily of calcium carbonate. Inside the shell, there are two membranes: the inner and outer shell membranes, which help prevent bacterial invasion. Within the egg, the albumen, or egg white, surrounds the yolk, which contains nutrients for the developing embryo. The chalazae are twisted strands of protein that anchor the yolk in the center of the egg. Together, these structures support the potential growth of a new life.