Classify carbohydrates with suitable examples.

1. 1 · Open in two lines. Carbohydrates are polyhydroxy aldehydes or ketones, or compounds that give them on hydrolysis. General formula Cn(H2O)n.
2. 2 · Draw a classification chart. [Chart: carbohydrates → monosaccharides, disaccharides, oligosaccharides, polysaccharides, with two examples under each]
3. 3 · Write the four groups.
   • Monosaccharides: one unit; trioses to hexoses, as aldoses (glucose) or ketoses (fructose).
   • Disaccharides: two units (sucrose, lactose, maltose).
   • Oligosaccharides: 3–10 units (raffinose, stachyose). Satyanarayana uses 2–10.
   • Polysaccharides: more than 10 units; homo (starch, glycogen, cellulose) and hetero (heparin, hyaluronic acid).
4. 4 · Significance. Main energy source in the Indian diet (rice, wheat, millets). Reducing sugars are detected by Benedict's test.
5. 5 · Nutrition link. Cellulose gives dietary fibre; raffinose in pulses causes gas; low lactase causes lactose intolerance.
6. 6 · Close in one line. Sum up that carbohydrates are classified by the number of sugar units they give on hydrolysis.

Scoring tip: A neat chart with two examples per group carries most of the marks. Add one Indian food example per group.