These are the simplest units or forms of carbohydrates that cannot be further split up by hydrolysis. They contain a single chain of carbon atoms. Important monosaccharides are the hexoses and the pentoses (containing six or five carbon atoms per molecule)
Hexoses:
Monosaccharides that are soluble in water and taste sweet are often called sugar. The three most important hexose sugars are glucose, fructose and galactose. Glucose and galactose are aldoses and fructose is a ketose. Some babies who have inherited an inability to use galactose in the milk on which they are fed suffer severe tissue injury- a condition known as galactosaemia. Such babies should be fed on foods other than milk.
This illustrates the fact that modes of arrangement of atoms in molecule are crucial to their biological functions. Galactose is useful in the liver function test when administered to a patient with a damaged liver; the galactose appears unchanged in the urine.
Hexoses:
Monosaccharides that are soluble in water and taste sweet are often called sugar. The three most important hexose sugars are glucose, fructose and galactose. Glucose and galactose are aldoses and fructose is a ketose. Some babies who have inherited an inability to use galactose in the milk on which they are fed suffer severe tissue injury- a condition known as galactosaemia. Such babies should be fed on foods other than milk.
This illustrates the fact that modes of arrangement of atoms in molecule are crucial to their biological functions. Galactose is useful in the liver function test when administered to a patient with a damaged liver; the galactose appears unchanged in the urine.
