All membranes are made up of fat and protein molecules. In cell membrane and cel
ID: 271267 • Letter: A
Question
All membranes are made up of fat and protein molecules. In cell membrane and cell organelles there are protein molecules in form of chain suspended in fat molecules (semi fluid). Both cell membrane and membrane around organelles are selectively permeable allowing water molecules to pass and restricting salts by osmosis. So, we can say that cell membrane and cell organelles have same structure and composition.
Q. According to that answer above do you have any examples of membranes merging together?
Explanation / Answer
Ans- yes merging of vesicular membranes with different organelles in cellular traficking is a very good example for the above explanation.
All the membranes have two faces one is cytoplasmic and other is exoplasmic. Lipid bilayer composition and protein composition are somewhat different from each other in both these faces.
Hence organelles such as endoplasmic reticulum, golgi bodies and transport vesicles all have their outer surface as cytoplasmic face and inner surface as exoplamic one but plasma membrane has its inner surface as cytoplasmic face and outer surface as exoplasmic one.
Vesicles that bud out from endoplasmic reticulum and fuses with golgi membranes has similar composition but those targeted for plasma membrane bud out from the golgi in an inside out composition to be able to get fused with the plasma membrane.