Explain the nutrition process in amoeba?

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 explain the nutrition process in amoeba?

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Amoeba nutrition involves five steps :

1. INGESTION

Ingestion involves taking in of food.

 

Amoeba do not have mouth, therefore food intake may take place from any part of the body, but it usually takes place at the advancing end i.e., pseudopodia. This process of obtaining food is called phagocytosis.

2. DIGESTION

Digestion is the breakdown of complex food molecules into simpler molecules through a series of chemical reaction carried out by various enzymes.In Amoeba, the food digestion occurs within the food vacuoles which, thus, act as temporary stomach. Digestive enzymes secreted by the cytoplasm are stored in the cytosomes. A lysosome full of enzymesfuses with each food vacuole and converts it into diffusible form. Enzymes reported for amoeba include :amylase, which converts starches to sugars, protease, which breaks proteins to amino acids, lipase, that changes fats to fatty acids and glycerol.
3. ABSORPTION
Absorption means taking up digested nutrient molecules into the cells of living organisms.In Amoeba, the soluble foods resulting from digestion diffuse through the food vacuoles into the surrounding cytoplasm. As absorption proceeds, the food vacuoles decrease in size till only the indigestible matter is left in them4.ASSIMILATION
 
The absorbed food is synthesised into protoplasm and this is known as assimilation. Some food is synthesised into storage products like glycogen and fats. Synthesis is aided by enzymes.

5. EGESTION

The removal of the undigested food is known as egestion.

In Amoeba, egestion may occur in any part of the body. The indigestible matter left in the food vacuoles is denser than the surrounding endoplasm. Such vacuoles finally come in contact with the plasmalemma. The plasmalemma ruptures at this point, and the indigested food is thrown out. Plasmalemma soon gets repaired to prevent the outflow of the endoplasm.

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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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detail of  amoeba ingestion by circumvallation

Circumfluence

When the prey is inactive and the amoeba rolls over it.

Circumfluence another type of ingestion of amoeba

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.

stages of egestion in amoeba

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.

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 Amoeba can constantly change its shape. It forms finger-like projections called pseudopodia (meaning false feet). around its prey and engulfs it. The food thus eaten gets trapped in the food vacuole. An Amoeba feeds on algae, rotifiers, protozoans, and even other small Amoeba. Digestive juices are secreted inside the food vacuole in an Amoeba. Theses juices act on the food and break it down into smaller components. The digested food is later absorbed by the Amoeba for growth, maintenance, and multiplication. The waste material or undigested food is then expelled out of the body.

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NUTRITION IN AMOEBAAmoeba nutrition involves five steps :1. INGESTIONIngestion involves taking in of food.Amoeba do not have mouth, therefore food intake may take place from any part of the body, but it usually takes place at the advancing end i.e., pseudopodia. This process of obtaining food is called phagocytosis.2. DIGESTIONDigestion is the breakdown of complex food molecules into simpler molecules through a series of chemical reactions carried out by various enzymes.In Amoeba, the food digestion occurs within the food vacuoles which, thus, act as temporary stomach. Digestive enzymes secreted by the cytoplasm are stored in the cytosomes. A lysosome full of enzymes fuses with each food vacuole and converts it into diffusible form. Enzymes reported for amoeba include : amylase, which converts starches to sugars, protease, which breaks proteins to amino acids, lipase, that changes fats to fatty acids and glycerol.3. ABSORPTIONAbsorption means taking up digested nutrient molecules into the cells of living organisms.In Amoeba, the soluble foods resulting from digestion diffuse through the food vacuoles into the surrounding cytoplasm. As absorption proceeds, the food vacuoles decrease in size till only the indigestible matter is left in them.4. ASSIMILATIONThe absorbed food is synthesised into protoplasm and this is known as assimilation. Some food is synthesised into storage products like glycogen and fats. Synthesis is aided by enzymes.5. EGESTIONThe removal of the undigested food is known as egestion.In Amoeba, egestion may occur in any part of the body. The indigestible matter left in the food vacuoles is denser than the surrounding endoplasm. Such vacuoles finally come in contact with the plasmalemma. The plasmalemma ruptures at this point, and the indigested food is thrown out. Plasmalemma soon gets repaired to prevent the outflow of the endoplasm.NUTRITION IN AMOEBAAmoeba nutrition involves five steps :1. INGESTIONIngestion involves taking in of food.Amoeba do not have mouth, therefore food intake may take place from any part of the body, but it usually takes place at the advancing end i.e., pseudopodia. This process of obtaining food is called phagocytosis.2. DIGESTIONDigestion is the breakdown of complex food molecules into simpler molecules through a series of chemical reactions carried out by various enzymes.In Amoeba, the food digestion occurs within the food vacuoles which, thus, act as temporary stomach. Digestive enzymes secreted by the cytoplasm are stored in the cytosomes. A lysosome full of enzymes fuses with each food vacuole and converts it into diffusible form. Enzymes reported for amoeba include : amylase, which converts starches to sugars, protease, which breaks proteins to amino acids, lipase, that changes fats to fatty acids and glycerol.3. ABSORPTIONAbsorption means taking up digested nutrient molecules into the cells of living organisms.In Amoeba, the soluble foods resulting from digestion diffuse through the food vacuoles into the surrounding cytoplasm. As absorption proceeds, the food vacuoles decrease in size till only the indigestible matter is left in them.4. ASSIMILATIONThe absorbed food is synthesised into protoplasm and this is known as assimilation. Some food is synthesised into storage products like glycogen and fats. Synthesis is aided by enzymes.5. EGESTIONThe removal of the undigested food is known as egestion.In Amoeba, egestion may occur in any part of the body. The indigestible matter left in the food vacuoles is denser than the surrounding endoplasm. Such vacuoles finally come in contact with the plasmalemma. The plasmalemma ruptures at this point, and the indigested food is thrown out. Plasmalemma soon gets repaired to prevent the outflow of the endoplasm.

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