Lecture Notes on Cells and Nutrition

Cells

• Definition: The smallest unit of life found in all living organisms.
• Importance of Cells:
  • Building blocks of organisms (like bricks for a building).
  • Fundamental unit for all living beings.

Types of Cells

• Living Organisms potentially made up of different types of cells:
  • Example: Ant vs. Elephant
    • Ant Cell: Smaller size, fewer cells.
    • Elephant Cell: Larger size, more numerous.

Cell Discovery

• First cell discovered using a microscope by Robert Hooke in 1665.
• Cells are categorized based on size and function:
  • Smallest: Bacteria (about 0.5 – 5 micrometers).
  • Largest: Ostrich egg.
  • Longest: Neuron (in some cases).

Components of Cells

• Structure of Cells:
  • Cell Membrane: Outer layer.
  • Nucleus: Control center.
  • Cytoplasm: Gel-like substance inside.

Organelles in Cells

• Endoplasmic Reticulum (ER): Transport system within the cell.
• Mitochondria: Powerhouse producing energy (ATP).
• Golgi Apparatus: Packages proteins.
• Lysosomes: Digest waste.

Cell Theory

• 1. All living organisms are made up of one or more cells.
• 2. The cell is the basic unit of life.
• 3. All cells arise from pre-existing cells.

Nutrition

• Components:
  • Macronutrients (Carbohydrates, Proteins, Fats).
  • Micronutrients (Vitamins and Minerals).

Macronutrients

1. Carbohydrates:
   • Basic energy source.
   • Found in: Grains, fruits, and vegetables.
2. Proteins:
   • Essential for growth and repair of tissues.
   • Found in: Meat, dairy, legumes, and nuts.
3. Fats:
   • Concentrated energy source.
   • Found in: Oils, butter, and nuts.
   • Two types:
     • Saturated (solid at room temperature)
     • Unsaturated (liquid at room temperature).

Micronutrients

1. Vitamins:
   • Fat-soluble (A, D, E, K) and water-soluble (B-complex and C).
   • Important for enzymatic reactions and bodily functions.
2. Minerals:
   • Essential for various body functions (Calcium, Iron, etc.).
   • Help form bones, blood components, and hormones.

Nutritional Needs

• Influenced by age, gender, physical activity, and specific health conditions.
• Balanced Diet:
  • Combination of all nutrients in sufficient quantities.
• Daily caloric intake varies by individual:
  • Young children: ~1100 calories
  • Adults: ~1600-2500 calories based on activity level.

Malnutrition

• Definition: Imbalance in nutrient intake.
• Types:
  • Deficiencies: Lack of essential nutrients can lead to diseases (e.g., Scurvy from Vitamin C deficiency, Rickets from Vitamin D deficiency).
• Malnutrition can affect growth, immune function, and overall health.

Conclusion

• Cells are the basic building blocks of life, fundamental for all organisms.
• Nutrition is critical for proper cellular function and overall health, requiring a balance of various nutrients.