A disaccharide is a saccharide formed from two monosaccharides by dehydration synthesis.
Polysaccharides = one sugar, such as glucose Disaccharides = linked sugars--two glucose forming maltose. Polysaccharides = many linked sugars--starch is an example of this.
A disaccharide forms when two monosaccharide molecules undergo a dehydration synthesis reaction, in which a water molecule is removed, leaving a covalent bond between the two monosaccharides. This process typically occurs during carbohydrate digestion and synthesis.
Monosaccharides are single sugar molecules, such as glucose and fructose, while disaccharides are made up of two monosaccharides linked together, like sucrose (glucose + fructose) and lactose (glucose + galactose). Monosaccharides are the building blocks of carbohydrates and can be quickly absorbed by the body, while disaccharides require more digestion to break down into monosaccharides for absorption.