No, they are not interchangeable because protoplasm is the living content of a cell that is surrounded by a plasma membrane (cell membrane). Protoplasm is composed of a mixture of small molecules such as ions, amino acids, monosaccharides and water, and macro-molecules such as nucleic acids, proteins, lipids and polysaccharides. In eukaryotes the protoplasm surrounding the cell nucleus is known as the cytoplasm and that inside the nucleus as the nucleoplasm.
