AI Tutor
If you sprint for ten seconds, your body burns tiny single sugar molecules, but if you run a marathon, it taps into giant branching chains stored in your muscles.
Both fuel sources are carbohydrates β€” biomolecules composed of carbon, hydrogen, and oxygen atoms typically arranged in a strict 1:2:11:2:1 ratio (C1H2O1C_1H_2O_1).
How do these simple atoms link together to build everything from sweet nectar to rigid tree trunks? Let's inspect the smallest building block first.

Monosaccharides: The Single Sugars

A monosaccharide is a single sugar ring and the fundamental monomer (individual building block) of all larger carbohydrates.
The most vital monosaccharide is glucose (C6H12O6C_6H_{12}O_6), the primary fuel that cellular respiration breaks down to produce cellular energy.
In 1891, German chemist Emil Fischer proved that glucose, fructose (fruit sugar), and galactose (milk sugar) share the exact same chemical formula (C6H12O6C_6H_{12}O_6), differing only in the 3D arrangement of their atoms.
What happens when a cell snaps two of these single sugar rings together?

Disaccharides: Double Sugars

A disaccharide is a carbohydrate formed when two monosaccharides join through dehydration synthesis, a reaction that removes a water molecule (H2OH_2O) to link the sugars.
The covalent link formed between the two sugar rings is called a glycosidic bond.