What are secretory vesicles and what functions do they perform?

[Ali Inam]

This might be a stupid question but as I am very new to biology, I am still unable to understand a lot of stuff.What are secretory vesicles and what functions do they perform ? !

 

[Kglocc]

Vesicles perform many functions through complex mechanisms that can involve many aspects of cell regulation.
Secretory vesicles in particular are specialized vesicles formed in the trans-golgi apparatus for releasing a product (such as molecule or protein) outside the cell.
Secretory vesicles are used for exocytosis.

Mast cells use secretory vesicles to release histamine which is a molecule
involved immune response.
Neurotransmitters can also be transmitted in secretory vesicles from nerve cells.

 

[Ali Inam]

So, we can say that secretory vesicles are a form of cell organelles, as you mentioned, that they contribute in the intracellular activities ? !

 

[arkofnoah]

i wouldn't call secretory vesicle a cell organelle because they only exist transiently in the cell. they are a part of the endomembrane system that shuttle newly synthesized proteins within the cell. for example some of the proteins and enzymes in mitochondria or in chloroplast are coded by the nuclear genome and these protein need to be transported to the mitochondria following transcription and translation. that's one of the job of these vesicles. so you can think of them as intracellular shuttle buses.

and of course the other job of these vesicles is exocytosis, which is basically how a cell releases chemicals, such as enzymes or hormones, out into the extracellular environment.

 

[Ali Inam]

So, mainly, they are the transporters of different chemicals and neurotransmitters in our body ? !Apart from taking part in the exocytosis

 

[Kglocc]

Mainly. Secretory vesicles are a more specific class of Vesicles in general.
You can count on vesicles holding and transporting various molecules around.

*** Note that Vesicles can perform other function in the cell besides transport

"Vesicle-
A bubble-like membranous structure that stores and transports cellular products, and digests metabolic wastes within the cell; an intracellular membranous sac that is separated from the cytosol by at least one lipid bilayer. "

http://www.biology-online.org/dictionary/Vesicle

 

[Ali Inam]

Oh Boy !


It stores, transports as well as Digests !

Surely, it must be an important content of the cell and also for the cell processes.



Thanks Everyone !