when a plant cell is plasmolysed what is left between the membrane and cell wall.?

Question

This was asked by one of my alevel biology students when doing a practical on red onion cells.

Answer 1

some teacher you are if you need to come onto YA to get an answer to a students question. Between the cell wall and the plasma membrane is mainly branched polysaccharides eg cellulose, pectin and glycans that compose the structure and anchoring of the cell wall to the membrane. As with all membranes there is some degree of permeability - after all a plant cell membrane is selective in what can pass- so will be surrounded with interstitial fluid which must therefore permeate the wall. It will also have protein channels etc to facilitate transport through the membrane. There are two zones to a wall; primary and secondary - the primary zone allows for growth, while the secondary is more rigid and aids in osmotic resistance. When the cell plasmolyses the whole structure bursts due to osmotic pressure - I would imagine that the same stuff would remain between the membrane and the wall, it is just in pieces. Cytoplasm is within the membrane's inner face ie the membrane surrounds and isolates the cytosol from the external environment - as is its role in living organisms.

Answer 2

Extracellular fluid is between cell wall and membrane.
Remember, that cell wall is premeable.