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Does any of you know the specific name of the protein rafts that allow proteins to float over a double layer of phospholipids, (cell membrane)? I just feel there should be another name rather than simply "protein raft".

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These conglomerations of proteins, glycolipids, and cholesterol are usually called lipid rafts. (Google Scholar shows 84,000 hits for that term, vs. 400 hits for "protein raft".) Here is a diagram of a lipid raft:

Lipid Raft in membrane

(Key: A: Intracellular space or cytosol, B: Extracellular space or vesicle/Golgi apparatus lumen. 1: Non-raft membrane. 2: Lipid raft. 3: Lipid raft associated transmembrane protein. 4: Non-raft membrane protein. 5: Glycosylation modifications (on glycoproteins and glycolipids). 6: GPI-anchored protein. 7: Cholesterol. 8: Glycolipid) [from Wikimedia Commons]

As this illustrates, lipid rafts float within the membrane lipid bilayer, not "over" or "above" it. The raft is a part of the membrane, not something outside it or on just one side of it. The raft is free to move in the surrounding two dimensions of the membrane.

One could argue that "protein raft" might be a better name than "lipid raft" since we would call a common raft a "wood raft" or "papyrus raft", but usually not a "water raft". Whatever the worth of such an argument, "lipid raft" is the term in use.

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    $\begingroup$ I was under impression defferent lipid composition (i.e. more cholesterol and shingolipids than in surrounding membrane) is the defining property of lipid raft. Therefore, I find your argument for "protein raft" being a better name misleading. $\endgroup$
    – BagiM
    Oct 17, 2019 at 5:45
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    $\begingroup$ I agree with @BagiM. Since the lipid composition is altered and that causes the change in rigidity, I think "lipid raft" is a nice name. The raft in your water analogy is made out of a water solution? Perhaps it is a stretched metahpore at that point... Purely semantic though. This is a good answer that clears up the confusion. $\endgroup$
    – James
    Oct 17, 2019 at 12:09
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There aren't protein rafts that "float" over a bilayer. There are proteins that insert domains into bilayers, or pass through them, or bind to lipid headgroups. There are also other proteins that bind to these proteins.

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