Explain what has to happen to join two monosaccharide units into a disaccharide.

Dehydration synthesis is the process by which two monosaccharide are joined to form a disaccharide.

Monosaccharides, known as simple sugar, is the simplest form of carbohydrates. Its basic molecular formula is CH2O. Monosaccharides are glucose, fructose, and galactose. Its primary function is to be the source of energy of living organisms. It is also the primary requirement for the formation of disaccharides and polysaccharides.

Disaccharides are formed when two monosaccharides are bonded together through a covalent bond. Common Dissaccharides are sucrose  (glucose+fructose) or table sugar, maltose (glucose+glucose), and lactose (glucose+galactose). Its primary function is to provide nutrition for monosaccharides. Sugar in food is mostly dissaccharides.

Ithink the dna sequences may vary but the amino acid sequences are identical.