Expert: John Locke - 7/24/2010

Question
what happens to an egg after it is taken into our mouth?what is the process of digestion of the egg?

Answer
Thanks for using AllExperts. Digestion includes the processes of mechanical digestion (the physical breaking down of food into smaller particles) and chemical digestion (the breaking of chemical bonds within the molecules of food). Eggs consist primarily of protein and fat, with some carbohydrate; these three types of molecules are the fundamental types of molecules found within food. These molecules are complex polymers of simpler units joined together to make larger compounds: carbohydrates are composed of simple sugars like glucose and fructose, fats are composed of multiple fatty acids, and proteins are composes of regularly joined amino acids.

Physical digestion begins in the mouth with mastication (chewing); chemical digestion begins with the enzyme amylase, which breaks down large carbohydrates into smaller sugars. The food then moves to the stomach, where acid is secreted along with an enzyme (pepsin) that together degrade proteins into their component amino acids. Physical digestion also occurs in the stomach, with vigorous crushing and thrashing of the food occurring during stomach contractions. The partially digested material, known as chyme, now moves to the small intestine, where the majority of digestion and absorption occurs. Fat is broken into smaller droplets by bile salts from the liver, then digested chemically by lipase from the pancreas. The partially degraded carbohydrates are broken down further by enzymes attached to the cells lining the small intestine. Finally, an enzyme from the pancreas known as trypsin digests the remaining proteins into their component amino acids. Amino acids, simple sugars, and broken-down fat molecules are absorbed through the cells lining the small intestine.

This is a broad overview of digestion, which is actually a very complex process. More specific information can be found easily online, detailing the specific steps and enzymes associated with each stage of the digestive process. Basically, however, digestion occurs in the mouth, stomach, and small intestine.