- How does amoeba gets its nutrition ?
Amoeba consumes food with the help of pseudopodia. Pseudopodia are temporary finger-like projections of the cell surface, which fuse over the food particle. This results in the formation of a food vacuole.
It is inside this food vacuole that complex substances are broken down into simpler ones. They are then diffused into the cell cytoplasm. The remaining undigested material is thrown out of the cell surface.
Amoeba feeds on other microscopic organisms such as ciliates and algae. These are ingested (taken into the cell) by pseudopodia, or "false feet". These are extensions of the cytoplasm which surround the prey and trap it in a tiny drop of water, forming a food vacuole. Enzymes are then added to the vaculoe to digest the food. Useful substances are absorbed into the cell while indigestible materials are passed out.
The unicellular AMEOBA engulfs tiny particles of food by throwing its false feet , known as PSEUDOPODIA around it . The Pseudopodia join together to form a small cavity known a a FOOD VACUOLE . The food inside the vacuole is digested by digestive juices . It is absorbed and assimilated there to provide energy and perform other functions .
Amoeba is a microphagous feeder, which means that it feeds upon small aquatic organisms like bacteria, flagellates, ciliates and minute food particles.
When a hungry Amoeba approaches to some food particle, it produces out its pseudopodia in the form of food cup which engulf the food particle by turning into food vacuole. the food also contain some water. this complete ingestion. the next step is digestion which is faciliated by the lysosomes. A few lysosomes surround the food vacuole and get fused with the membrane to discharge their enzymatic contents(proteases, amylases and lipases)into it. Hence the digestion is intacellular. At this stage the vacuole becomes a digestive vacuole. It decrease in size as the water is withdrawn and its content first become acidic(pH 5.6) and then alkaline. When the digestion is completed, the digestive vacuole membrane is drawn into numerous fine canals. the soluble food particles are passed into the canals and finally into the surrounding cytoplasm by micropinocytosis. the digested food, water and minerals are absorbed(absorption) into the cytoplasm and circulate in it, through cyclosis where the food is assimilated into new protoplasm or is oxidized to librate energy. the undigested food is egested by exocytosis at the rear end.