Cytoskeleton

• Cytoskeleton


  An extensive network of protein fibres within the cytoplasm of cells
• Types of protein fibres in the cytoskeleton

  • Microfilaments
  • Microtubules
  • Intermediate filaments
• Microfilaments


  • Solid strands mostly made of the protein actin
  • Can cause some cell movement and the movement of some organelles within cells by moving against each other
• Microtubules


  • Tubular (hollow) strands mostly made of the protein tubulin
  • Organelles and other cell contents are moved along these fibres using ATP to drive this movement
• Intermediate filaments


  • A third type of fibre found within the cytoskeleton
• Functions of the cytoskeleton

  • Strengthening and support
  • Intracellular (within cell) movement
  • Cellular movement
• Strengthening and support


  • Provides the cell with mechanical strength, forming a 'scaffolding' that helps to maintain the shape of the cell
  • Supports the organelles, keeping them in position
• Intracellular (within cell) movement

  • Aids transport within cells by forming 'tracks' along which organelles can move
  • Examples include the movement of vesicles and the movement of chromosomes to opposite ends of a cell during cell division
• Cellular movement


  • Enables cell movement via cilia and flagella
  • Cilia and flagella are hair-like extensions that protrude from the cell surface and contain microtubules that are responsible for moving them
• Organelles held in position by the cytoskeleton

  • Mitochondrion
  • Endoplasmic reticulum