GENERAL

• HOW DO MUSCLES MOVE?

  sliding filament mechanism
• WHAT ARE MYOFIBRILS MADE UP OF?

  myosin, actin, tropomyosin (and troponin)
• WHAT IS MYOSIN?

  made up of two types of protein

  • TAIL: fibrous protein arranged into a filament made up of several hundred molecules
  • HEAD: globular protein formed into two bulbous structures at one end
• WHAT IS ACTIN?

  globular protein whose molecules are arranged into long chains that are twisted around one another creating a helical strand
• WHAT IS TROPOMYOSIN?

  forms long, thin threads that are wound around actin filaments