What is protoplasm? Who gave the term protoplasm?

Protoplasm is the living substance within a cell, comprising all the contents enclosed by the cell membrane including both the cytoplasm and the nucleus. It represents the complete living material of the cell and consists of water (75-85%), proteins, lipids, carbohydrates, nucleic acids, and inorganic salts in a complex colloidal state. Often described as the "physical basis of life," protoplasm exhibits characteristic properties such as metabolism, growth, reproduction, responsiveness to stimuli, and the ability to repair itself, which collectively define living matter.

The term "protoplasm" was coined by Jan Evangelista Purkyně, a Czech physiologist, in 1839, though the concept was later popularized and refined by Hugo von Mohl and other scientists. While the term is somewhat outdated in modern cell biology—having been largely replaced by more specific terms like cytoplasm, nucleoplasm, and cytosol—it remains historically significant as one of the first attempts to identify and name the essential living material common to all cells. Understanding protoplasm as the site of all vital cellular activities was a crucial step in establishing cell theory and recognizing the fundamental unity of life across all organisms.