🍼 2. Lactose (Milk Sugar)
- Made from: One glucose and one galactose molecule.
- Bond: A 1,4-glycosidic bond, where galactose is linked to glucose.
- Where it is found: Only in milk of mammals — humans, cows, goats.
- Why important: It provides energy to baby mammals, including human infants.
🧠 Mnemonic for Lactose:
“Lactose = Little baby energy sugar”
Helps remember it’s in milk and important for babies.
🧃 Real-life connection:
People who can’t digest lactose properly are called lactose intolerant — they often avoid dairy products like milk or yogurt because their body lacks the enzyme lactase, which breaks lactose down.
🍬 3. Sucrose (Cane Sugar / Table Sugar)
- Made from: One glucose + one fructose.
- Bond: 1,2-glycosidic bond (carbon 1 of glucose to carbon 2 of fructose).
- Molecular formula: C₁₂H₂₂O₁₁
- Where it is found: It’s the sugar we use at home — found in sugarcane, sugar beets, and as the main sweetener in most foods.
- Why important: Gives quick energy and adds sweetness to food.
💡 Mnemonic to remember Sucrose:
“Sucre = Sugar”
(“Sucre” means sugar in French — think of Sucrose = Sugar for sweetness.)
🍰 Real-life analogy:
Think of sucrose as a celebrity sugar — it’s the one you sprinkle on your tea or use in baking cakes!
✨ Summary Chart for Quick Review
| Disaccharide | Made of | Found in | Bond Type | Function |
| Maltose | Glucose + Glucose | Cereals, starch digestion | 1,4-glycosidic | Intermediate energy source |
| Lactose | Glucose + Galactose | Mammalian milk | 1,4-glycosidic | Energy source for infants |
| Sucrose | Glucose + Fructose | Sugarcane, table sugar | 1,2-glycosidic | Sweetener, quick energy |
🧠 Final Mnemonic to Remember Disaccharides:
“MaLaSu — Maltose, Lactose, Sucrose“
Use the phrase: “MaLaSu gives you sweet energy!“