The term protoplasm includes both the substance within and the cell membrane and is the " living substance" of the cell. It can be differentiated into cytoplasm and the nucleus.
Physical properties of protoplasm.
It is a transparent and jelly-like material, the consistency varying from the more liquid, slightly gelatinous white of a fresh egg to that of semi-solidified gelatin of jelly. If the protoplasm is more liquid it is termed a sol, if more gelatinous, a gel.Chemical properties of protoplasm.
The chemical properties of protoplasm can be divided into inorganic and organic substances.
Inorganic substances are water, which make up 90% of the protoplasm, mineral salts, such as NaCl-salt, and gases like oxygen and carbon dioxide.
Organic substances include proteins, carbohydrates, lipids, nucleic acids and enzymes.
Cells divide to form identical daughter cells; function of the nucleus of the protoplasm, e.g. the meristematic region of angiosperms.
The living protoplasm responds to stimuli, e.g. retinal cells in the eye respond to light.
All these functions are carried out inside the cell, e.g. respiration in the mitochondria;
Cells must get rid of excretory wastes; they usually diffuse out of the cell through the cell membrane.
Movement is exhibited by certain cells, e.g. unicells; the protoplasm of these cells has a contractile ability.
Growth follows on cell division; there is an assimilation of protoplasm and an increase in size.