1. The complex, semifluid, translucent substance that constitutes the living matter of plant and animal cells and clearly presents the essential life functions of a cell.

Composed of proteins, fats, and other molecules suspended in water, it includes the nucleus and cytoplasm.

2. The colorless liquid or jelly contents of a living cell, composed of proteins, fats, and other organic substances in water and which is regarded as the physical basis of all living matter and life functions.

At first, Czech physiologist Jan Evangelista Purkinje gave the name protoplasm to the living material within the cell, in 1839.

He referred specifically to the gelatinous embryonic material in an egg because this first-formed material reminded him of the word protoplasm which was used to describe Adam, the first formed man, in the Bible.