Zytoplasmas

Zytoplasmas, in English cytoplasm, refers to the gel-like substance inside a cell that lies within the plasma membrane and surrounds the nucleus in eukaryotes. It comprises the cytosol, a viscous fluid containing water, ions, small molecules, and soluble proteins, and the organelles suspended within it.

In eukaryotic cells the cytoplasm includes organelles such as mitochondria, endoplasmic reticulum, Golgi apparatus, lysosomes, peroxisomes, and the cytoskeleton. In prokaryotic cells the cytoplasm also fills the cell but lacks membrane-bound organelles; ribosomes and enzyme complexes are dispersed in the cytoplasm, and genetic material resides in a nucleoid region.

Functions: The cytoplasm provides a medium for biochemical reactions; glycolysis and various metabolic pathways occur in the cytosol. It supports intracellular transport, distributes metabolites, and hosts protein synthesis on free ribosomes or those attached to the endoplasmic reticulum. It maintains cell shape and enables movement through the cytoskeleton, and it stores inclusions such as glycogen or lipid droplets in certain cells.

Structure and dynamics: The cytoplasm is highly dynamic, with the composition and viscosity depending on cell type, developmental stage, and physiological conditions. It is bounded by the plasma membrane, and in eukaryotes the outer nuclear membrane is continuous with the endoplasmic reticulum, while the nucleus lies separate within the cell.