Question

Explain why chemists

refer to the joining of monosaccharides molecules to form disaccharides as a "dehydration
synthesis" reaction. (aka: condensation reaction).

Answer 1

The joining of monosaccharides to form disaccharides is called dehydration synthesis because it involves the removal of a water molecule as a new glycosidic bond forms between the sugar molecules.

Step-by-step explanation:

Chemists refer to the joining of monosaccharides molecules to form disaccharides as "dehydration synthesis" or a "condensation reaction" because during this process, a molecule of water (H₂O) is released. This happens when the hydroxyl group (-OH) of one monosaccharide combines with the hydrogen atom (H) of another, resulting in the formation of a covalent bond known as a glycosidic bond or glycosidic linkage. These bonds can be alpha or beta type, which differ in the orientation of the OH group on the first glucose's carbon-1, affecting the shape and properties of the resulting disaccharide. This reaction is also known as a condensation reaction because it involves the synthesis of a larger molecule from smaller subunits.

Answer 2

It is referred to as a hydration/condensation reaction because this reaction involves the production of a water molecule as a by-product of the formation of the glycosidic bond. When two monosaccharides join, the 4’ C of one monomer forms a covalent bond the 1’ C of the other. One Carbon loses an –OH while the other a –H during the formation of this bond. An H+ and an OH- then combine to form a water molecule.