Sucrose is the chemical compound that makes up ordinary table sugar. It is a disaccharide built from a glucose unit and a fructose unit joined by a glycosidic bond. The linkage connects the anomeric carbon of glucose to the anomeric carbon of fructose.
A glycosidic linkage joins the two monosaccharide residues. Once linked, the atoms belong to one sucrose molecule; sucrose is not a physical mixture of free glucose and free fructose molecules.
This equation is a composition relationship for forming the glycosidic linkage, not a claim that biological sucrose synthesis proceeds as one uncatalysed elementary dehydration step.
A sucrose molecule contains 45 atoms in total. Formula composition alone does not reveal that those atoms are organised into linked glucose-derived and fructose-derived rings.
This is the structural feature behind one of sucrose's most useful distinctions: sucrose is a nonreducing disaccharide because neither anomeric carbon remains as a free hemiacetal/hemiketal centre that can readily open to the corresponding carbonyl form.
Hydrolysis adds the elements of water across the linkage. The process can be catalysed by acid or by enzymes such as sucrase/invertase, depending on context.
Its glycosidic bond joins C1 of the glucose residue and C2 of the fructose residue, the anomeric centres of both monosaccharide units. Neither remains as a free hemiacetal or hemiketal that can equilibrate with a free carbonyl form.
Not in the same way. Because both anomeric centres are locked in the glycosidic linkage, sucrose does not have a free anomeric hydroxyl that can open and reclose to interconvert α and β anomers of the intact disaccharide.
No. The term covers multiple saccharides. Glucose and fructose are monosaccharides with C₆H₁₂O₆; sucrose is a disaccharide with C₁₂H₂₂O₁₁.
| Molecular formula | C₁₂H₂₂O₁₁ |
|---|---|
| Molar mass | 342.2965 g/mol |
| CAS Registry Number | 57-50-1 |
| PubChem CID | 5988 |
| Structural description | α-D-glucopyranosyl-(1→2)-β-D-fructofuranoside |
| Chemical class | Nonreducing disaccharide |
An aldohexose with a free anomeric centre in its cyclic hemiacetal forms.
A ketohexose with the same molecular formula as glucose but different connectivity.
Both monosaccharide anomeric centres participate in the glycosidic linkage.