Cytoskeleton
The cytoskeleton is an internal network of protein filaments that supports cell shape and organizes movement, transport, and division.
Actin filament: A thin, dynamic polymer of actin proteins that supports cell shape and generates force. Actin filaments drive shape changes, crawling, and contraction.
Cytoskeletal dynamics: The continual assembly, disassembly, and remodeling of cytoskeletal filaments. Rapid remodeling lets cells change shape and reorganize their internal framework.
Intracellular transport: The movement of molecules and organelles within a cell. Cytoskeletal tracks and motors provide directed routes for cellular cargo.
Extracellular matrix: A network of molecules outside cells that provides tissue structure and biochemical cues. It supports tissues from outside, while the cytoskeleton organizes structure within cells.
Microtubule: A hollow polymer of tubulin proteins that organizes intracellular transport, cell shape, and chromosome movement. Microtubules form the cell’s long-range tracks and division apparatus.
Molecular motor: A protein that converts chemical energy into directed movement along a molecular track or against a load. Motor proteins move cargo and generate force through interactions with cytoskeletal filaments.
Cell migration: The directed movement of cells across or through their surroundings. Actin remodeling and adhesion changes propel migrating cells.
Cell wall: A rigid extracellular layer that surrounds many cells, including plants, fungi, and bacteria. Cell walls provide external rigidity rather than an adaptable internal filament network.
Intermediate filament: A rope-like protein polymer that resists mechanical stress in cells and tissues. Intermediate filaments provide tensile strength where the other filaments are more dynamic.
Kinesin: A family of motor proteins that generally carries cargo toward microtubule plus ends. Kinesin drives much of the outward transport along microtubules.