Glucose vs Fructose: what is the difference?
Glucose and fructose share the formula C6H12O6, but glucose forms a six-membered ring and fructose a five-membered one, and fructose is far sweeter.
Sources and notes
- The sentence under the titlefrom sourceMoleculeFinder comparison notesThe pair's answer line.
- The two drawingscomputedMoleculeFinder rule (RDKit MCS)Each molecule's own drawing, as its page shows it. The common core, 2 of 12 atoms, is too small to align on.
Side by side
| Glucose | Fructose | |
|---|---|---|
| Molecular weightCalculated PubChem | 180.16 g/molC6H12O6 | 180.16 g/molC6H12O6 |
| Hydrogen-bond donorsCalculated PubChem | 5 | 5 |
| SweetnessMeasured HSDB via PubChem; Weber et al. 2025 | 0.74× sugar | 1.73× sugar |
| Against table sugar, which is 1. | ||
| Where each turns upEditorial MoleculeFinder food and product lists |
| |
| FamilyEditorial MoleculeFinder curated | Sugars | Sugars |
| Everyday groupEditorial MoleculeFinder curated | Sweetener | Sweetener |
| Chemical groupsCalculated Found by rule (RDKit) | Alcohols, Ethers | Alcohols, Ketones |
| Oral LD50Measured HSDB via PubChem | 25,800 mg/kgpure glucose, rat, oral | Not recorded |
| A single acute animal measure. It ranks nothing about human safety. | ||
Sources and notes
- Molecular weightcomputedPubChemComputed from the structure; the formula is under each weight.
- Hydrogen-bond donorscomputedPubChemThe hydrogens on nitrogen or oxygen that each molecule can lend to a hydrogen bond, counted from its structure.
- Sweetnessfrom sourceHSDB via PubChem; Weber et al. 2025
- Where each turns upfrom sourceMoleculeFinder food and product listsEach amount is an editorial figure from our lists, not a measurement of any one product. Each mark is set by hand on the list, never inferred.
- Familyfrom sourceMoleculeFinder curated
- Everyday groupfrom sourceMoleculeFinder curated
- Chemical groupscomputedFound by rule (RDKit)Each group is found in the structure by a chemical pattern.
- Oral LD50from sourceHSDB via PubChem
- Identifiersfrom sourcePubChemPubChem CID 5793 (Glucose) and 5984 (Fructose).
In more detail
Their weights are identical too, and fructose carries a ketone where glucose has an aldehyde. That difference decides where each goes. Nearly every cell in the body can burn glucose directly, and blood sugar means glucose specifically, while fructose is handled almost entirely by the liver. Fructose is the sweeter of the two by a wide margin, which is why fruit tastes sweeter than its sugar content alone suggests. Table sugar is one of each joined together, and high-fructose corn syrup is the same two sugars unjoined and slightly rebalanced.
Sources and notes
- The paragraphfrom sourceMoleculeFinder comparison notes
Questions
- What is the difference between Glucose and Fructose?
- Glucose and fructose share the formula C6H12O6, but glucose forms a six-membered ring and fructose a five-membered one, and fructose is far sweeter.
- Do Glucose and Fructose have the same formula?
- Yes. Both are C6H12O6 at 180.16 g/mol. They are isomers: the same atoms arranged differently, which is why they behave differently despite weighing the same.
- Is Glucose sweeter than Fructose?
- Fructose is the sweeter of the two, about 1.73 times as sweet as table sugar against about 0.74 times for Glucose. Sweetness here is measured against sucrose, which is defined as 1.
Sources and notes
- The answersfrom sourceMoleculeFinderThe first is the pair's answer line; the others are read off the table above.