BIOCHEM | Monosaccharides

Monosaccharides

also known as simple sugars, they have 1 sugar unit and smallest unit of any carbohydrate

Types of Monosaccharides

glucose, galactose, fructose, and mannose

Glycoside Formation

• monosaccharides + alcohol to form a glycoside

• has an acetal and ketal linkage

• has sugar bound to other functional group

Glycoside Formation Reaction Steps

1. Protonation: add H+

2. Formation of Oxonium Ion

3. Nucleophilic Attack: Atom with extra pair of electrons attacks the positive charge

4. Glycoside Bond Forms

5. Release of Water as Byproduct

Oxidation

loss of electron through removal of H or addition of O

Reagent

reacts with main compound

Aldonic Reaction

reacts with aldehyde group

Uronic Reaction

reacts with primary alcohol group

Aldaric Reactions

reacts with both aldehyde group and primary alcohol group

Reduction

• Gain of electron through oxidizing agent

• Conversion of the carbonyl group (aldehyde or ketone) to a hydroxyl group, forming a sugar alcohol

Fructose

fruit sugar, found in plants

Galactose

milk sugar, found in dairy

Glucose

blood sugar, primary energy source

Mannose

seen in human metabolism

Ribose

component of ribonucleotide