Question

Which statement best describes transcytosis?

1) Combining an endosome with a lysosome and degrading or releasing the contents
2) Transporting an endosome from one side of a cell to the other and releasing the contents by exocytosis
3) Recycling the contents of the endosome back to the surface of the cell
4) Storing the contents of the endosome

Answer 1

Transcytosis is best described as the transport of an endosome across a cell and releasing contents via exocytosis. Hence, the correct answer is option (2).

Step-by-step explanation:

The statement that best describes transcytosis is: 2) Transporting an endosome from one side of a cell to the other and releasing the contents by exocytosis. Transcytosis is a cellular process that combines aspects of endocytosis and exocytosis to move substances across the cell.

During transcytosis:

Endocytosis: The cell takes up material (macromolecules, particles, etc.) from the extracellular environment through endocytosis, forming vesicles.

Transport: The vesicles containing the internalized material move across the cell's cytoplasm.

Exocytosis: The vesicles fuse with the cell membrane on the opposite side, releasing the material into the extracellular space.

Transcytosis is important for various physiological processes, including the transfer of antibodies from a mother to her baby through breast milk (IgG transcytosis) and the selective transport of molecules across epithelial barriers. It allows cells to regulate the movement of specific substances between different compartments or environments.