CYTOSKELETON

• Cytoskeleton

  • network of protein fibres
  • provides cell structure and shape
  • internal framework
  • assist movement
• Cytoskeleton components

  • microfilaments
  • microtubules
  • intermediate filaments
• Microfilaments - TINY


  • 7 nm
  • actin
  • involved in muscle contractions
  • involved in cytoplasmic streaming (creates a current for movement of chloroplasts)
  • involved in cell mobility (phagocytes, amoeba, requires ATP)
• Intermediate filaments - MODERATE

  • 8-12 nm
  • keratin
  • anchors organelles in place
• Microtubules - LARGEST

  • 25 nm
  • TUBULIN
  • movement of organelles, chromosomes, the cell itself, flagella and cilia
• Centrioles - made from microtubules

  • two centrioles - centrisome
  • involved in cell division
  • form the spindle
  • located next to the nucleus
• Cilia and flagella


  • 9 + 2 arrangement of microtubules
• Cilia


  • present in greater numbers
  • beat to create movement, requires ATP
  • move mucus in trachea
• Flagella


  • enables mobility
  • whip like structure
  • sensory - can detect chemical changes in an environment