🍽️ Nutrition & Digestive System
Modes of Nutrition
| Autotrophs | Heterotrophs |
|---|---|
| Manufacture own organic compounds from inorganic raw materials | Obtain organic molecules from environment as food |
| Example: Plants, Algae, Some bacteria | Example: Animals, Fungi |
Carnivorous Plants
- True autotrophs that supplement diet with insects
- Typically live in nitrogen-deficient habitats
- Examples: Pitcher Plant, Venus Fly Trap, Sundew
- Digestion via bacteria or enzymes secreted by leaves
🌟 Did You Know? The human digestive tract is approximately 9 meters (30 feet) long from mouth to anus!
🫁 Gaseous Exchange & Respiratory System
Respiratory Surface Properties
- Must be moist and permeable for gas diffusion
- Should be thin (≤1mm) for efficient diffusion
- Requires large surface area and good blood supply
- Needs ventilation mechanism to maintain diffusion gradient
Transport of Respiratory Gases
- Oxygen: 97% as oxyhemoglobin in RBCs, 3% dissolved in plasma
- Carbon Dioxide: 70% as bicarbonate ions, 23% as carbaminohemoglobin, 7% dissolved
- Chloride shift (Hamburger’s phenomenon) maintains ionic balance
🌿 Transport in Plants
Water Uptake & Ascent of Sap
- Root hairs provide 67% of total absorption surface
- Three pathways: Apoplast, Symplast, Vacuolar
- TACT Theory: Transpiration pull, Adhesion, Cohesion, Tension
- Water can be pulled up to 200 meters in tall trees
Translocation of Organic Solutes
- Movement through phloem tissue
- Direction: from source to sink
- Explained by Pressure Flow/Mass Flow theory
- Phloem sap contains ~90% sucrose
❤️ Transport in Humans & Cardiovascular System
The Human Heart
- Hollow, fibromuscular organ with 4 chambers
- Located in chest cavity between lungs, slightly left of sternum
- Right side: pumps deoxygenated blood to lungs
- Left side: pumps oxygenated blood to body
- Cardiac cycle duration: 0.8 seconds
Blood Components
| Component | Function | Count per mm³ |
|---|---|---|
| Red Blood Cells | Oxygen transport | 4-5.5 million |
| White Blood Cells | Immune defense | 7,000-8,000 |
| Platelets | Blood clotting | 250,000 |
🛡️ Lymphatic & Immune System
Three Lines of Defense
- First Line: Physical barriers (skin, mucous membranes)
- Second Line: Non-specific defenses (phagocytes, inflammation, fever)
- Third Line: Specific immune response (B-cells, T-cells, antibodies)
Types of Immunity
| Type | Mechanism | Examples |
|---|---|---|
| Innate Immunity | Non-specific, present at birth | Skin, stomach acid, phagocytes |
| Acquired Active | Develops after exposure to antigen | Vaccination, recovering from infection |
| Acquired Passive | Antibodies transferred from another source | Maternal antibodies, antiserum |
🚀 Study Strategies
1
Create Process Flowcharts
Draw detailed flowcharts for: Digestive pathway (mouth → anus), Respiratory pathway (nostrils → alveoli), Blood circulation (heart → body → heart).
2
Compare Animal vs Plant Transport
Make tables comparing: Open vs closed circulation, Blood vs sap composition, Heart vs root pressure mechanisms.
3
Memorize Enzyme Functions
Create flashcards for digestive enzymes: Amylase (carbs), Pepsin/Trypsin (proteins), Lipase (fats), and their sites of action.