Monosaccharides: Glucose, Fructose, and Galactose

• Glucose, fructose, and galactose are monosaccharides, which are simple sugars.
• Sucrose, maltose, lactose, glycogen, and starch are complex carbohydrates, composed of multiple monosaccharide units.

Glucose

• Glucose is a monosaccharide with the molecular formula C6H12O6.
• Often referred to as blood sugar, as it's the primary sugar found in the bloodstream.
• It serves as the main source of energy for cells in the body.
• The basic building block for many carbohydrates.

Fructose

• Fructose is a monosaccharide that has the same molecular formula as glucose (C6H12O6) but a different structural arrangement.
• It is known as fruit sugar because it is abundantly found in fruits.
• It is the sweetest naturally occurring sugar.

Galactose

• Galactose is a monosaccharide with the formula C6H12O6, similar to glucose and fructose.
• It is not usually found in nature alone.
• Commonly part of the disaccharide lactose, found in milk.
• Converted to glucose for energy metabolism.

Sucrose

• Sucrose is a disaccharide composed of one glucose molecule and one fructose molecule linked together.
• Commonly known as table sugar.
• It is extracted from sugar cane or sugar beets.
• During digestion, it is broken down into glucose and fructose.

Maltose

• Maltose is a disaccharide formed from two glucose molecules joined together.
• Also known as malt sugar.
• Produced during the germination of certain grains, like barley.
• It is broken down into glucose units during digestion.

Lactose

• Lactose is a disaccharide composed of one glucose molecule and one galactose molecule.
• It is the primary sugar found in milk, hence the name milk sugar.
• Individuals with lactose intolerance have difficulty digesting lactose due to a deficiency of the enzyme lactase.
• Broken down into glucose and galactose during digestion.

Glycogen

• Glycogen is a polysaccharide made up of many glucose molecules linked together.
• It serves as the primary form of glucose storage in animals and is stored mainly in the liver and muscles.
• When the body needs glucose, glycogen is broken down into glucose molecules through glycogenolysis.

Starch

• Starch is a polysaccharide composed of many glucose molecules linked together.
• It is the primary form of glucose storage in plants.
• Found in foods like potatoes, rice, wheat, and corn.
• During digestion, starch is broken down into glucose molecules through enzymatic action.

This lesson explores three monosaccharides: glucose, fructose, and galactose. Glucose, or blood sugar, is the body's primary energy source. Fructose, found in fruits, is the sweetest natural sugar. Galactose is a component of lactose and is converted to glucose for energy.