What is the Difference Between Constitutive and Regulated Exocytosis?

The main difference between constitutive and regulated exocytosis lies in the manner in which secretory materials are released.

Constitutive Exocytosis:

• Secretory materials are continuously released by all cells.
• Serves the release of components of the extracellular matrix or delivery of newly synthesized membrane proteins.
• The rate of constitutive exocytosis is well controlled.
• Examples include cells producing and secreting proteoglycans and glycoproteins of the extracellular matrix.

Regulated Exocytosis:

• Secretory materials are stably accumulated in secretory vesicles as storage sites.
• Requires an external signal and a specific sorting signal on the vesicles.
• Triggered when a cell receives a signal from the outside.
• Examples include the release of cytokines, hormones, neurotransmitters, and other small signaling molecules.

Both constitutive and regulated exocytosis involve the process by which cells release molecules to the outside of the cell. The key difference between the two is that constitutive exocytosis continuously releases secretory materials, while regulated exocytosis releases secretory materials in a stable manner in secretory vesicles as storage sites.

Comparative Table: Constitutive vs Regulated Exocytosis

Here is a table summarizing the differences between constitutive and regulated exocytosis:

Please note that some of the information in the table is based on the text provided in the search results rather than direct quotes.