Digestion in Amoeba
Amoeba is a unicellular organism that follows a simple mode of nutrition known as holozoic nutrition. It engulfs food particles and digests them inside its body through intracellular digestion.
Structure of Amoeba
Amoeba has an irregular, shapeless body consisting of the following parts:
- Cell membrane: A thin outer layer that regulates the movement of substances.
- Cytoplasm: A jelly-like substance inside the cell, divided into the outer ectoplasm and inner endoplasm.
- Nucleus: Controls all activities of the Amoeba, including reproduction.
- Pseudopodia: Temporary extensions of the cytoplasm that help in movement and capturing food.
- Food vacuole: Formed around the engulfed food, where digestion occurs.
- Contractile vacuole: Maintains water balance by expelling excess water.
Process of Nutrition in Amoeba
The nutrition process in Amoeba occurs in the following steps:
1. Ingestion (Food Intake)
- Amoeba extends its pseudopodia around the food particle (such as bacteria or algae).
- The food is engulfed inside a food vacuole by a process called phagocytosis.
2. Digestion (Breaking Down of Food)
- Enzymes from the cytoplasm enter the food vacuole and break down complex food into simpler substances.
- This digestion process is intracellular and occurs inside the food vacuole.
3. Absorption (Nutrient Uptake)
- The digested nutrients are absorbed into the cytoplasm.
- These nutrients provide energy for growth and other activities.
4. Assimilation (Utilization of Nutrients)
- The absorbed nutrients are used for energy production, growth, and repair of the Amoeba’s body.
- The food is assimilated into different parts of the cell for various functions.
5. Egestion (Removal of Waste)
- The undigested food is expelled from the cell by moving to the surface and releasing it through exocytosis.
- This helps in maintaining a clean internal environment.