Epidermis cell, A before and B after plasmolysis. Before plasmolysis, in A, the plasma membrane is appressed against the cell wall. Like in all plant cells the vacuole is surrounded by a thin membrane: the tonoplast. Some epidermal cells of red onions contain purple anthocyanes in their vacuoles. It is easier to distinguish the barrier between cytoplasm and vacuoles in these cells. After plasmolysis, in B, the cytoplasm has shrunken. The plasma membrane is detached from the cell wall. Due to severe plasmolysis even the vacuole has shrunken. |