When starch is digested, which monosaccharides are released?

Expert Answers

An illustration of the letter 'A' in a speech bubbles

Hydrolysis is the process by which large polymers are broken down into their sub-- units known as monomers. These monomers are small molecules that are repeated inside the larger polymer and held together by covalent bonds.

Starch is a polysaccharide-- a polymer composed of a long chain of glucose...

See
This Answer Now

Start your 48-hour free trial to unlock this answer and thousands more. Enjoy eNotes ad-free and cancel anytime.

Get 48 Hours Free Access

Hydrolysis is the process by which large polymers are broken down into their sub-- units known as monomers. These monomers are small molecules that are repeated inside the larger polymer and held together by covalent bonds.

Starch is a polysaccharide-- a polymer composed of a long chain of glucose molecules which are monomers. Enzymes known as amylases and maltases help to facilitate the hydrolysis of starch, which breaks the bonds between glucose molecules. These bonds are called glycosidic linkages. 

By the addition of water, the hydrogen atom from the water attaches to one monomer and the hydroxyl group (OH) attaches to the adjacent monomer. This causes the chemical bond between two adjacent glucose molecules to break down during digestion of starch. The first step forms a disaccharide called maltose. Later, maltose sugar is further hydrolyzed to form the simple sugar glucose --a monosaccharide. Starch digestion begins in the mouth where enzymes are present in saliva and completes in the small intestine. 

A monosaccharide has the general formula of CH2O. The monosaccharide which makes up starch is glucose-- C6H12O6 a hexose sugar. Starch is a polysaccharide composed entirely of the monosaccharide glucose.

After starch digestion, glucose becomes available as an energy source for cellular work.

I have included a link showing the breakdown of starch to glucose.

 

Approved by eNotes Editorial Team