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search Plant cells have strong walls, and inside the wall is a
cell membrane, then a thin layer of cytoplasm with the nucleus
and other organelles in it. The cytoplasm is pressed against the
cell wall by the very large vacuole. In this picture the cell
nuclei are dark-coloured.  Protoplasm is an old term, which
means the living substance that makes up a cell. It is no longer
much used. Biologists prefer to talk about the cytoplasm and the
cell nucleus.  In plant cells, it is surrounded by a cell wall.
In animal cells, the whole cell is made of protoplasm,
surrounded by a cell membrane. Protoplasm in living beings is
made up of about 75–80% water. However, this is rather
misleading because the cytoplasm is full of structures called
organelles, which do various tasks. The endoplasmic reticulum is
the largest of these structures; there are many other
organelles.  The word "protoplasm" was first used in 1846 by
Hugo von Mohl to describe the substance in p