Sitoplasma

Sitoplasma, or cytoplasm, is the jelly-like substance inside cells. In eukaryotes it lies between the plasma membrane and the nucleus; in prokaryotes it fills the interior of the cell. The cytoplasm comprises the cytosol, a complex aqueous solution, plus organelles and various inclusions. The cytosol is the fluid component containing dissolved ions, metabolites, enzymes, and the machinery of many metabolic pathways; ribosomes suspended in the cytosol carry out protein synthesis.

Organelles embedded in the cytoplasm include mitochondria, chloroplasts (in plants and algae), the endoplasmic reticulum, the Golgi apparatus, lysosomes, peroxisomes, and other specialized bodies. The cytoplasm also contains the cytoskeleton, a network of microtubules, actin filaments, and intermediate filaments that provides shape, mechanical support, and tracks for organelle and vesicle movement.

Major functions of the cytoplasm include hosting numerous metabolic pathways, providing a medium for biochemical reactions, and supporting the growth and division of the cell. It is the site of glycolysis in many cells and of the early steps of macromolecule synthesis. Protein synthesis occurs on ribosomes that can be free in the cytosol or attached to the rough endoplasmic reticulum, with newly formed proteins targeted to their destinations via cytoplasmic trafficking.

In prokaryotes, the cytoplasm contains the nucleoid region with the genome, ribosomes, and various inclusion bodies, but lacks membrane-bound organelles. The cytoplasm is a dynamic, crowded environment essential to cellular physiology and homeostasis.