Nutrition in amoeba is holozoic. Thus, solid food particles are ingested which are then acted upon by enzymes and digested. It is an omnivore, feeding on both plants and animals. Its diet includes bacteria, microscopic plants like the diatoms, minute algae, microscopic animals like other protozoa, nematodes and even dead organic matter.
Since it is a unicellular organism, amoeba does not have any specialised structure or organ for the process of nutrition. It takes place through the general body surface with the help of pseudopodia.
.Ingestion- Ingestion involves taking in of food
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Circumfluence
When the prey is inactive and the amoeba rolls over it.
Egestion
The egestion takes place by exocytosis. There is no particular point from which the egestion takes place. As the amoeba moves forward, the undigested matter is shifted to the back and eliminated as food pellets through a temporary opening formed at any nearest point on the plasmalemma.
Absorption
Since the food on digestion is converted into liquid diffusible form, it is readily absorbed by the cytoplasm. The vacuole becomes progressively smaller as the food is absorbed by diffusion.
Assimilation
All the parts of the cell get the nutrients by the cyclic movement of the cytoplasm called the cyclosis. These nutrients are used to build new protoplasm. In this manner the food is assimilated