Definition

Noun: A microscopically small, hollow, cylindrical protein structure found in the cytoplasm of eukaryotic cells. Microtubules are a key component of the cytoskeleton and are involved in maintaining cell shape, enabling intracellular transport, and facilitating cell division (mitosis and meiosis).

Usage

Microtubules function as structural supports and "highways" for molecular transport within the cell. They are dynamic structures that can rapidly assemble and disassemble.

Examples

• The microtubule network is essential for maintaining the elongated shape of nerve cells.
• During mitosis, microtubules form the mitotic spindle, which separates chromosomes.
• Motor proteins like kinesin walk along microtubules to transport vesicles.

Advanced Usage

• Microtubule-associated proteins (MAPs): Proteins that bind to microtubules to regulate their stability and function.
  • Tau is a MAP that stabilizes neuronal microtubules.
• Microtubule-organizing center (MTOC): A cellular structure, such as the centrosome, from which microtubules nucleate and grow.
  • The centrosome serves as the primary MTOC in animal cells.

Variants and Related Words

• Microtubular (adj): Of or relating to microtubules.
  • The microtubular cytoskeleton was visualized under the microscope.

Synonyms

• Cytoskeletal filament
• (In context) Spindle fiber

Related Phrases and Concepts

• Microtubule polymerization/depolymerization: The process of assembly and disassembly of tubulin subunits into microtubules.
  • The drug inhibits cancer cell division by promoting microtubule depolymerization.
• Microtubule destabilizing/stabilizing agent: A compound that interferes with microtubule dynamics.
  • Colchicine is a classic microtubule destabilizing agent.

Noun

1. a microscopically small tubule