cytoplasms

The cytoplasm refers to the material inside a cell, excluding the nucleus. In eukaryotic cells it includes the cytosol, a gel-like aqueous phase, together with the organelles and cytoplasmic inclusions suspended within it. In prokaryotic cells, which lack a defined nucleus, the term generally denotes the entire interior of the cell membrane that is not bounded by a nucleus.

Cytoplasm is composed of several components. The cytosol contains water, ions, small molecules, and a wide array of enzymes that drive metabolic reactions. Embedded in the cytoplasm are membrane-bound organelles such as mitochondria, endoplasmic reticulum, Golgi apparatus, lysosomes, and peroxisomes, as well as non-membrane structures like ribosomes and elements of the cytoskeleton (microfilaments, intermediate filaments, and microtubules). Cytoplasmic inclusions, including storage granules and lipid droplets, may also be present depending on the cell’s type and state.

Functions of the cytoplasm include hosting many metabolic pathways, such as glycolysis in the cytosol and various steps of biosynthesis and degradation. It provides a medium for molecular transport, supports intracellular organization, and facilitates signaling and response to stimuli. The cytoskeleton within the cytoplasm maintains cell shape, enables movement, and guides the distribution of organelles. In some plant and fungal cells, cytoplasmic streaming helps distribute nutrients and organelles within the cell.

Overall, the cytoplasm is a dynamic and essential component of cells, balancing biochemical activity with structural organization to support cellular life.