Are cell membrane and membranes of the organelles differently composed?
1 Answer
Yes, they are. The cell membrane is a lipid bilayer while the organelle membranes are usually a single layer of lipids.
The nucleus, mitochondria and chloroplasts are the exception and have a lipid bilayer.
Cell membranes have numerous attached membrane proteins.
These proteins take various forms single- or multipass transmembrane proteins, tunnel-shaped proteins similar to ion channels, and proteins that attach to one side of the lipid membrane.
Proteins located on the outside of the plasma membrane of eukaryotic cells often have oligosaccharide chains attached. These are often involved in "self" recognition.
The nature of the plasma membrane varies greatly depending on its' lipid composition including cholesterol.
Each organelle has very own proteins with specific functions. These differ from the proteins on the cell membrane.
