What is the fluid portion of the cytoplasm called?

The fluid portion of the cytoplasm is called cytosol. Cytosol is the aqueous component within the cell where various organelles, particles, and proteins are suspended. It plays a crucial role in cellular processes by facilitating biochemical reactions and providing structural support to the cell.

While cytoplasm refers to the entire content within the cell membrane excluding the nucleus, which includes both the cytosol and the organelles, the term cytosol specifically designates just the fluid part. Protoplasm is a more general term that encompasses both the cytoplasm and the nucleoplasm, which is the fluid in the nucleus, making it broader than what is being asked. Cell sap is typically associated with plant cells, referring to the fluid found in the vacuoles and is not synonymous with cytosol. Hence, cytosol is the most precise term for the fluid portion of cytoplasm.