The Cytoskeleton

The Cytoskeleton

1. PROTEIN FIBRES

   • Micro/Actin filaments
     • Made of F and G actin subunits
     • Smallest of the protein fibres
     • Involved in cell movement
     • Each actin molecule has a Mg ion binding site
     • Requires lots of ATP to make ADP +Pi formed
   • Micotubules
     • Made from Alpha and Beta Tubulin fibres
     • Largest of the protein fibres
     • They involved in intracellular transport, cell division
     • Motorway system to all areas of the cell
   • Intermediate Filament
     • Middle Size
     • Made of tetramers formed of proteins
     • Mechanical strength and structural support
     • Rope like, across the whole cell
     • Involved in cell-cell interaction
   • WHAT IS IT MADE OUT OF?

2. WHAT ROLE DOES IT HAVE?

   • Gives the cell a mobile shape
   • Allows the cell to move
   • Intercellular transport
   • Responsive to inter and extra celluar signals

3. WHAT IS IT?

   • A framework of proteins made up of three subunits
   • Made from subunit proteins which form polymers

4. POLYMERISATION

   • Nucleation (lag phase)
     • Small sunits may form together to form oligomer
   • Elongation (growth phase)
     • Subunits only add on one side of the molecule (+) end
   • Steady State (equilibrium phase)
     • Where the rate of subunit addition and loss are equal
       • Called the critical condition =Cc
     • Accessory proteins increases the speed of the process
   • Requires lots of ATP

Images and files in the map