Starchy foods, such as potatoes, bread, rice, pasta and cereal, would provide you with little caloric value were it not for the presence of amylase in your digestive system. Amylase is a digestive protein, or enzyme, which breaks down dietary starch into smaller subunits that are further digested and absorbed from your small intestine. Your pancreas and salivary glands in your mouth produce amylase.
Salivary Amylase
Your salivary glands secrete a mucus-like fluid, commonly referred to as spit, in response to food aromas or the presence of food in your mouth. Salivary amylase, also known as ptyalin, is the only digestive enzyme found in your mouth. Ptyalin begins the digestion of starch as you chew and swallow food. The digestive process stops temporarily in your stomach because stomach acid inactivates salivary amylase.
Pancreatic Amylase
You may not think of your pancreas as a digestive organ, but food breakdown cannot occur without its help. Situated behind your stomach and next to the first portion of your small intestine, your pancreas produces the bulk of your digestive enzymes --- including pancreatic amylase. As food passes from your stomach into your bowel, your pancreas releases digestive enzymes and fluids through a small tube that connects the organs. Amylase mixes into the liquefied food and resumes the breakdown of dietary starch that began in your mouth.
Breakdown Product
Dietary starches consist of long strands of sugar molecules joined by chemical bonds. Amylase breaks some of the chemical bonds in starch molecules via a process called hydrolysis. The sugar, maltose is the primary breakdown product of amylase-digested starch. Maltose is a simple sugar comprised to two glucose molecules joined together. Your intestinal cells produce another enzyme, maltase, which breaks the bond between the glucose molecules in maltose. Free glucose then enters your bloodstream; your organs and tissues take up glucose and use it to generate energy.
Digestive Conditions Affecting Amylase
Your blood amylase level can rise to abnormal levels with certain disorders of your digestive system. Pancreatitis, or inflammation of your pancreas, commonly causes an elevated blood amylase level because the enzyme leaks from the inflamed organ into your bloodstream. Possible causes of pancreatitis include alcohol abuse, cystic fibrosis, gallstones and abdominal trauma. Problems with your salivary glands can also cause an elevated blood amylase level. Mumps, salivary gland tumors or a stone in your salivary gland may elevate your blood amylase. Your doctor can order a laboratory test to determine whether your pancreas or salivary glands are the primary source of an elevated blood amylase level.
References
- "A Textbook of Medicinal Biochemistry"; R.L. Nath, M.Sc., Ph.D.; 2002
- Johns Hopkins Medicine: The Pancreas; June 2011
- Colorado State University Pathophysiology Hypertext; Exocrine Secretions of the Pancreas; Richard Bowen, D.V.M., Ph.D.; July 2006
- National Institute of Diabetes and Digestive and Kidney Diseases; Pancreatitis; July 2008
- "Clinical Biochemistry: Metabolic and Clinical Aspects"; William J. Marshall, M.A., Ph.D., M.B.B.S., Stephen K. Bangert, M.A., M.Sc., M.R.C.P; 1995
