endosomeilla

Endosomes are membrane-bound organelles found in eukaryotic cells. They are a key component of the endocytic pathway, a process by which cells internalize molecules from outside the cell. Endosomes form when vesicles containing extracellular material fuse with the plasma membrane and bud inward. These newly formed vesicles then mature into early endosomes, which are typically located near the cell periphery.

Early endosomes have a relatively neutral pH and play a role in sorting internalized material. From early endosomes, cargo can be directed to several destinations. Some material is recycled back to the plasma membrane, while other material is sent to late endosomes. Late endosomes are characterized by a more acidic pH and are often found closer to the cell nucleus.

Within late endosomes, molecules are further processed. Lysosomes, which contain hydrolytic enzymes, then fuse with late endosomes to form endolysosomes. This fusion delivers the internalized cargo to the degradative environment of the lysosome, where it is broken down into smaller components that can be reused by the cell. The endosomal pathway is crucial for nutrient uptake, receptor recycling, and the removal of pathogens and cellular debris. Disruptions in endosome function can lead to various diseases.