Video Transcript
Which digestive enzyme, produced by
the salivary gland and pancreas, helps break down starch?
Starch is a large carbohydrate
molecule that is present in many different types of food, such as bread and
pasta. Each molecule of starch can consist
of up to thousands of glucose molecules. Starch is too large to be absorbed
directly into the bloodstream, so first it needs to be broken down into individual
glucose molecules that are small enough for this absorption to occur.
The breakdown of starch into
glucose involves digestive enzymes that are produced by certain glands in the
body. First, starch is broken down into
disaccharides called maltose. The term disaccharide literally
means two sugars, as disaccharides like maltose consist of two simple sugar
molecules bound together. In contrast, starch is a
polysaccharide, as the prefix poly- means many, and it’s made of many sugars joined
together, while glucose is a monosaccharide, as it’s only made of one simple sugar
molecule. And the prefix mono- means one.
The digestive enzyme that catalyzes
the breakdown of starch into maltose is called amylase. The breakdown of starch is
completed by a digestive enzyme called maltase, which breaks down maltose into
individual glucose monomers. Now we need to know which of the
digestive enzymes, amylase or maltase, is produced by the salivary glands and
pancreas.
The breakdown of starch starts
immediately as food is placed into the mouth, as amylase that is present in saliva
begins to break down starch into maltose. Saliva and the amylase enzymes it
contains is produced in and secreted from the salivary glands, which are located in
the area surrounding the mouth.
By the time starch reaches the
small intestine, much of it will have already been broken down into maltose. However, some starch molecules will
remain. To break down the remaining starch
molecules into maltose, the pancreas also releases amylase enzymes into the first
part of the small intestine, which is called the duodenum.
Now we have enough information to
answer our question. The digestive enzyme produced by
the salivary glands and pancreas that helps break down starch is amylase.
