SHEET /vs/lactose-vs-galactose · COMPARISON
Lactose vs Galactose: what is the difference?
How they differ
Lactose is milk sugar and galactose is one of its two halves, so this pair is a molecule and its component rather than two competitors. Lactose is glucose joined to galactose at 342.3; splitting it needs the enzyme lactase, and most adults worldwide stop making enough lactase after childhood, which is what lactose intolerance is. Galactose alone is 180.16 and has the same formula as glucose, differing only in the orientation of one hydroxyl group. Babies handle both easily, and a rare inherited inability to process galactose is screened for at birth in many countries. Neither is especially sweet: lactose is one of the least sweet common sugars, which is why milk does not taste sugary.
Side by side
| Lactose | Galactose | |
|---|---|---|
| Formula | C12H22O11 | C6H12O6 |
| Molecular weight | 342.3 g/mol | 180.16 g/mol |
| Family | Sugars | Sugars |
| Everyday group | Sweetener | Sweetener |
| Functional groups | Alcohols, Ethers | Alcohols, Ethers |
| GHS signal wordThe supplier-filed hazard label, not a statement about ordinary use. | not recorded | Warning |
| Found in | Chocolate, Milk | not recorded |
| CAS number | 5965-66-2 | 59-23-4 |
| PubChem CID | 6134 | 6036 |
Structural similarity 0.61 of 1, computed as a Morgan fingerprint Tanimoto coefficient. It measures shape, not effect.
Common questions
- What is the difference between Lactose and Galactose?
- Lactose is milk sugar and galactose is one of its two halves, so this pair is a molecule and its component rather than two competitors. Lactose is glucose joined to galactose at 342.3; splitting it needs the enzyme lactase, and most adults worldwide stop making enough lactase after childhood, which is what lactose intolerance is. Galactose alone is 180.16 and has the same formula as glucose, differing only in the orientation of one hydroxyl group.
- Is Lactose bigger than Galactose?
- Lactose is the heavier molecule, 342.3 g/mol against 180.16 g/mol for Galactose. Lactose is C12H22O11 and Galactose is C6H12O6.