Anatomy of an Egg By: Hannah Flood

Contents/ Parts of an egg Shell Inner and Outer membrane Air Cell Albumen Chalazae Vitelline Membrane Yolk References

Shell Bumpy and Grainy texture. Covered with 17,000 tiny pores. Made of calcium carbonate crystals. It is a semi permeable membrane. Also has a thin coating called the bloom. Third bulletin-Which means that air and moisture can pass through its pores. Last bulletin-It helps keep the bacteria out.

Inner and Outer Membrane They lie between the eggshell and egg white. They are transparent protein membranes. They are really strong. Partly made out of keratin. One membrane sticks to the shell. The other surrounds the albumen. Second bulletin-The help provide defense against bacterial invasion. Fourth bulletin-Which is a protein that is also found in human hair.

Air Cell Forms when egg cools and contracts after being laid. It rests between the inner and outer membranes at the egg’s larger end. The fresher the egg the smaller the air cell. It grows bigger the older the egg gets. Second bulletin-Which can form a crater when it is hard-cooked.

Albumen Four thick and thin layers. Contains more than 40 different proteins. When broken the thick albumen stands up around the yolk. Albumen comes from the Latin word albus which means white.

Chalazae Opaque ropes of egg white. Holds the yolk in the center of the egg. They attach the yolk’s casing to the membrane lining the eggshell. The more noticeable they are the fresher the egg. Unnoticeable when the egg is cooked.

Vitelline Membrane The clear casing that encloses the egg. The fresher the egg the stronger the membrane will be.

Yolk Contains water, Protein, some fat, and most of the vitamins and minerals of the egg. It includes Iron, vitamin A, vitamin D, Phosphorous, calcium, thiamine, and riboflavin. Also a source of lecithin. Color ranges from a hint of yellow to a bright orange. Third bulletin-An effective emulsifier. Last bulletin-It depends on the chicken was feed and the breed it is.

References http://www.exploratorium.edu/cooking/eggs/eggcomposition.html http://msucares.com/poultry/reproductions/poultry_parts_embryo.html http://www.oeuf.ca/en/encyclopedie/oeufnatomie/ http://www.sxc.hu/pic/m/s/sf/sfxmystica/148222_the_egg_yolk_series_1.jpg