Amino Acids & Amylase

Amylase is a digestive enzyme that exists within your body as a few different types. Amylase starts working in your mouth, but it is also secreted by your pancreas into the small intestine. The role of amylase is to break down starch and other carbohydrates into simple sugars that can be absorbed and utilized for energy. Amylase is a protein made from long chains of amino acids, but as a digestive enzyme it does not metabolize dietary protein into amino acids.

Amylase

Amylase is a protein-based enzyme that catalyses the breakdown of starch into simpler sugars, such as disaccharides and trisaccharides, according to "Biochemical, Physiological and Molecular Aspects of Human Nutrition." Other enzymes are needed to reduce these simpler sugars into glucose, which is what your cells burn to produce energy. Amylase is in your saliva, which is why starchy foods that contain little sugar, such as rice and potatoes, start to taste sweet as you chew them. Plants and some bacteria also produce amylase. People produce a few different types of amylase.

Types of Amylase

The main types of amylase your body utilizes for digestion are alpha-amylase and beta-amylase. Alpha-amylase can only function in the presence of calcium and acts by breaking down starch at random locations, yielding maltotriose and maltose sugars, as cited in "Advanced Nutrition and Human Metabolism." Because it can act anywhere on the starch substrate, alpha-amylase tends to be faster-acting than beta-amylase. By contrast, beta-amylase can only break down starch at specific locations.

Alpha-Amylase

Alpha-amylase is the major digestive enzyme in all animals and works best in a pH range between 6.7 and 7.0, according to "Biochemistry of Human Nutrition." Alpha-amylase is produced by your salivary glands and your pancreas. Like all enzymes, alpha-amylase is made of amino acids and is considered a protein. When an enzyme is formed, it is made by stringing together between 100 and 1,000 amino acids in a very specific and unique order. The chain of amino acids then folds into a unique shape. That shape allows the enzyme to carry out specific chemical reactions. According to "Nutritional Sciences," alpha-amylase consists of 496 amino acids arranged in a single polypeptide chain and its formation is encoded on chromosome number one within your DNA.

Protein Digestion

Digesting protein, such as meat, legumes and seeds, requires enzymes different than amylase. Protein digestion occurs mainly in your stomach and small intestine and involves hydrochloric acid, pepsin and pancreatic enzymes. Pancreatic enzymes eventually reduce protein into individual amino acids that are absorbed through your small intestine and travel in the bloodstream to the liver. Once there, they are recycled into other proteins and used for replacing hair, fingernails, skin and other connective tissue.

References

• "Biochemical, Physiological and Molecular Aspects of Human Nutrition"; Martha Stipanuk; 2006
• "Advanced Nutrition and Human Metabolism: 5th Edition"; Sareen S. Gropper and Jack L. Smith; 2009
• "Biochemistry of Human Nutrition"; George Gropper; 2000
• "Nutritional Sciences"; Michelle McGuire; 2007