The Role of Digestive Enzymes
Enzymes are proteins that act as catalysts by accelerating the chemical reactions. Enzyme
lock and key theory is when the enzyme-substrate interaction suggests that the enzyme and
the substrate possess specific shapes that fit exactly into one another. Like a key into a lock,
only the correct size and shape of the substrate would fit into the active site of the enzyme.
(See lock and key model below)
Examples include:
Lipase
The body uses it to break down fats in foods so they can be absorbed. Peptic lipase is
located in the stomach and is operated best in acidic conditions of pH of 4.5. Lipase is also
produced in the pancreas and requires a pH of 7-9 as well as in the saliva (Lingual Lipase)
which requires a pH of 3.5. (Mount Sunai, 20)
Amylase
It is produced in the pancreas as well as some salivary glands. It is an enzyme or special
protein that helps you digest carbohydrates; it catalyses the hydrolysis of starch into sugars.
Amylase works most efficiently at pH 7.
Protease
Is produced in the pancreas, they break down peptide bonds of proteins. These enzymes
can be obtained from plants or animals. Protease also works best at pH of 7.
(See hand drawn image of Peptide bond from biology dictionary)
6
Enzymes are proteins that act as catalysts by accelerating the chemical reactions. Enzyme
lock and key theory is when the enzyme-substrate interaction suggests that the enzyme and
the substrate possess specific shapes that fit exactly into one another. Like a key into a lock,
only the correct size and shape of the substrate would fit into the active site of the enzyme.
(See lock and key model below)
Examples include:
Lipase
The body uses it to break down fats in foods so they can be absorbed. Peptic lipase is
located in the stomach and is operated best in acidic conditions of pH of 4.5. Lipase is also
produced in the pancreas and requires a pH of 7-9 as well as in the saliva (Lingual Lipase)
which requires a pH of 3.5. (Mount Sunai, 20)
Amylase
It is produced in the pancreas as well as some salivary glands. It is an enzyme or special
protein that helps you digest carbohydrates; it catalyses the hydrolysis of starch into sugars.
Amylase works most efficiently at pH 7.
Protease
Is produced in the pancreas, they break down peptide bonds of proteins. These enzymes
can be obtained from plants or animals. Protease also works best at pH of 7.
(See hand drawn image of Peptide bond from biology dictionary)
6
