[BetaAmyloid]

For an introduction, since this is my first time on these forums, I would just like to say that I am a 17-year-old student interested in the medical field (specifically biochemistry) and I am currently researching and writing a book on cancer. All other information I would like to not yet disclose, since there is the opportunity of someone copying information.

Anyways, to my question:

In the cell, or surrounding the cell, there is a phospholipid bilayer with different "pieces" of tail and head groups. Do the organelles in the cell contain the same cellular membrane as the cell itself, respectively?

Thanks,
The Cancer Curer

[Yggdrasil]

No.  Although all membranes in the cell are composed of phospholipids (plus additional components such as proteins, glycolipids, cholesterol, etc.) and exchange segments of membrane with each other, the exact composition of phospholipids differs between different compartments of the cell.  For example, whereas the ER has a relatively high amount of glycerophospholipids and low amounts of cholesterol and sphingolipids while the plasma membrane has relatively low amount of glycerophospholipids but higher amounts of cholesterol and sphingolipids.  Another example is the phosphorylation state of phosphatidylinositols, which differs among the various membrane systems of the cell and is used to help target cytoplasmic proteins to specific organelles.

Note that the lipid composition of membranes can also differ within the same cellular compartment (for example, lipid microdomains [also referred to as lipid rafts] are areas of the plasma membrane with different lipid compositions than the surrounding lipids), and lipid composition can differ within the same bilayer (for example, the outer leaflet of the plasma membrane has a very different lipid composition than the inner leaflet of the plasma membrane).

[BetaAmyloid]

Yggdrasil,

Okay, so to clarify, membranes of the cell itself and organelles DO consist of the same components respectively but still differ in terms of actual, specified components themselves, such as the cholestoral, serine, choline, protein, etc.

Thanks,
The Cancer Curer

[Yggdrasil]

Yes.

[BetaAmyloid]

Alright, thanks, I'll be sure to post more questions and answers!

Thanks,
The Cancer Curer