Question

Differentiate between intracellular and extracellular digestion.

Answer 1

Hint: It involves the chemical breakdown of large molecules of food into smaller components that can be absorbed into the bloodstream.

Complete answer:
Intracellular and extracellular digestion are two methods of digestion of food in heterotrophic organisms. These organisms obtain energy via the ingestion of energy-rich food. The ingested food gets degraded into small components with the help of the enzyme. Intracellular digestion takes place in unicellular organisms such as protozoans while extracellular digestion occurs in animals and fungi.

Difference between extracellular and intracellular digestion:

Intracellular digestion	Extracellular digestion
In intracellular digestion, the breakdown of food materials into small molecules occurs inside the food vacuoles within the cell.	In extracellular digestion, the breakdown of food materials into small molecules occurs outside the cell in the lumen of the alimentary canal or on the decaying organic materials.
In this type of digestion, the ingestion occurs through the phagocytic vesicles.	In this type of digestion, ingestion occurs through the mouth.
Digestive enzymes involve lysozyme that secretes into the food vacuole.	In this digestion, digestive enzymes secreted from the glands of the alimentary canal.
In intracellular digestion, only chemical digestion takes place.	In extracellular digestion, both chemical and mechanical digestion occurs.
Nutrients formed by this type of digestion diffuses into the cytoplasm through the membrane of the vacuole.	Nutrients formed by this type of digestion are absorbed into the blood through the gut epithelia.
The materials that are not digestible get excreted through the exocytosis.	The materials that are not digestible get excreted through the anus.
It is a simple mechanism of digestion that involves vesicles.	It is a complex mechanism of digestion that involves the organs and glands.
It mainly occurs in protozoans.	It follows in bacteria, fungi, and animals with the alimentary canal

Note: -Intracellular digestion involves two types of digestion: heterophagy and autophagy and they both occur in lysosomes.
-In heterophasic intracellular digestion, the breakdown of all molecules takes place in the cell by endocytosis.
-Autophagy preserves energy sources in the cell by recycling the damaged proteins, aggregates, and organelles in the cell.