* Monosaccharides:

* Glucose: The primary sugar used for energy by the body. It's found in many foods, especially fruits and starchy vegetables.

* Fructose: Found naturally in fruits and honey.

* Galactose: Found in dairy products.

* Disaccharides:

* Sucrose: Common table sugar, made up of glucose and fructose.

* Lactose: Milk sugar, made up of glucose and galactose.

* Maltose: Malt sugar, made up of two glucose molecules.

Digestion Process:

1. Mouth: Enzymes in saliva begin the breakdown of starch into simpler sugars.

2. Small Intestine: Here, enzymes break down disaccharides into monosaccharides.

3. Absorption: Monosaccharides are absorbed into the bloodstream and transported to the liver, where they are either used for energy or stored as glycogen.

Undigestible Sugars:

* Polysaccharides: Complex sugars like starch and fiber are not fully digested by humans, although some fiber can be fermented by bacteria in the gut.

* Artificial sweeteners: These are not sugars and do not require digestion.

Important Note: While humans can digest all of the above sugars, excessive intake of refined sugars like sucrose can have negative health consequences.