Microtubules form part of the mitotic spindle that moves the chromosomes during cell division. Microtubules also form the core of motile appendages known as cilia and flagella. Actin filaments also generate movement within the cytosol of eukaryotes. Actin filaments generate bulk movement of the cytoplasm know as cytoplasmic streaming, as well as a crawling type of locomotion of the cell as a whole. They also move plasma membrane during cell division.
Intermediate filaments provide important structural support and anchoring in the cytoskeleton.
These tubules and filaments do not occur in prokaryotes. Prokaryotes can move due to flagella which differ in chemical makeup from those of eukaryotes. Metabolic reactions occur everywhere in the cell, but those most central to the flow of energy are localized to the cytoplasm. Reactions involved in initial breakdown of energy-rich nutrients occur in the cytosol . In eukaryotes, this occurs in mitochondria .