Life processes are the basic functions that all living organisms perform to stay alive. These
include nutrition, respiration, transportation, and excretion.
1. Nutrition
Nutrition is the process by which organisms take in food and utilize it for energy, growth,
and repair.
Types of Nutrition:
1. Autotrophic Nutrition – Organisms make their own food (e.g., green plants).
Equation: CO₂ + H₂O —(Sunlight + Chlorophyll)—> Glucose + O₂
2. Heterotrophic Nutrition – Organisms depend on others for food.
- Holozoic (Human), Saprophytic (Fungi), Parasitic (Leech)
Nutrition in Human Beings
Digestive system includes: Mouth, Oesophagus, Stomach, Small Intestine, Large Intestine,
and Anus.
Enzymes help to break complex food into simple forms. Main digestive juices: Saliva
(amylase), Gastric juice (pepsin, HCl), Bile, and Pancreatic juice.
2. Respiration
Respiration is the process of breaking down food to release energy in the form of ATP.
Type Description
Aerobic Respiration Occurs with oxygen. Glucose → CO₂ + H₂O +
Energy.
Anaerobic Respiration Occurs without oxygen. Glucose → Alcohol
+ CO₂ + less energy.
Breathing means air in and out. Respiration includes energy release by food breakdown.
3. Transportation
Transportation is the process of moving materials like food, oxygen, and wastes in living
beings.
In Human Beings
The circulatory system includes Heart, Blood, and Blood Vessels.
• Arteries carry oxygenated blood away from heart.
• Veins bring deoxygenated blood to heart.
, • Capillaries connect arteries and veins.
Blood has RBC (carry O₂), WBC (fight infection), Platelets (help clotting).
[Diagram: Structure of Human Heart]