Nutrition Flashcards - Class 9 ICSE

Nutrition (Overview)

• Nutrition is the supply of essential organic and inorganic chemical compounds (nutrients) required for growth, energy, repair, and regulation.
• Nutrients are chemical compounds in food required for growth, energy, repair, and regulation (e.g., carbohydrates, proteins, fats, vitamins, minerals, water). [content from transcript indicates examples but is truncated; standard examples are listed here for completeness]
• Food vs Diet:
  • Food: any substance we eat or drink that contains nutrients.
  • Diet: the combination of food items eaten.
• Balanced diet: a diet that supplies all the necessary nutrients in correct amounts for proper body functioning.

Carbohydrates

• Carbohydrates are compounds of carbon, hydrogen, and oxygen in the ratio 2:1 (H:O).
• Main functions: principal energy source of the body; 1 mole of glucose releases 686\ \text{kcal} of energy.
• Monosaccharides (simple sugars): glucose, fructose, and galactose.
• Disaccharides and their components:
  • Sucrose = Glucose + Fructose
  • Maltose = Glucose + Glucose
  • Lactose = Glucose + Galactose
• Storage form in plants: starch (an insoluble polysaccharide).
• Cellulose and glycogen:
  • Cellulose: Found in plant cell walls; provides roughage.
  • Glycogen: Storage form of carbohydrates in animals.
• Roughage:
  • Non-digestible cellulose that helps in bowel movement, prevents constipation, and stimulates intestine.
• Sources of roughage: vegetables, fruits, cabbage, wheat (dalia).

Fats

• Fats are composed of carbon, hydrogen, and oxygen (with less oxygen than in carbohydrates).
• Energy value: 1\ \text{g fat} \rightarrow 9.45\ \text{kcal} (more energy per gram than carbohydrates).
• Functions of fat:
  1. Produces energy.
  2. Storage form of food.
  3. Solvent for fat-soluble vitamins.
  4. Provides insulation.

Proteins

• Proteins are large molecules of C, H, O, and N (sometimes S and P).
• Building blocks: amino acids.
• Main functions: growth and repair of body cells/tissues; in emergency, proteins may also provide energy.
• Kwashiorkor: Severe protein deficiency in children. Symptoms: underweight, swollen belly, dark/scaly skin, stunted growth.
• Treatment: By giving a protein-rich diet including pulses, milk, egg, fish, meat, soybean, and jaggery.

Connections & implications:

• Emphasis on a balanced intake of macronutrients (carbohydrates, fats, proteins) and essential micronutrients for healthy growth and bodily function.
• Understanding protein-energy malnutrition (e.g., Kwashiorkor) highlights the need for adequate protein in childhood nutrition and targeted dietary strategies.
• The role of roughage in digestion underscores the importance of dietary fiber in maintaining bowel health.
• Energy values (e.g., 686\ \text{kcal} per mole of glucose and 9.45\ \text{kcal} per gram of fat) illustrate how different macronutrients contribute to daily energy requirements and why proportionate intake matters.