Dictionary > Thick filament

Thick filament

Definition
noun, plural: thick filaments
A type of myofilament that is made up of bipolar myosin II filaments, and is approximately 12-14 nm in diameter
Supplement
Each myofibril of a muscle fiber is comprised of myofilaments. In striated muscle the myofilaments are arranged in repeating pattern units called sarcomeres. When viewed under the microscope the sarcomere appears as dark and pale bands. These bands are due to the arrangement of the myofilaments in the muscle fiber in a regular fashion. There are two main types of myofilaments, the thin filaments and the thick filaments. The thin filament is about 7-9 nm in diameter. In contrast, the thick filament is about 12-14 nm in diameter. The thick filament is made up of bipolar, elongated proteins called myosin. There are about 300-500 myosin molecules in a sarcomere and they are located at the center of the sarcomere. 1 A myosin molecule looks like two golf clubs intertwined, with the heads pointing out from the surface of the thick filament.2 The myosin tails bind together, forming the core of the thick filament. 1 The core is a central bare zone without projecting heads and formed from antiparallel arrays of LMM regions of the myosin heavy chains. Thick filaments will self assemble in vitro under the right ionic conditions.
Compare:

See also:

  • myosin
  • sarcomere
  • muscle fiber
  • muscle
  • Reference(s):

    1 Thick Filaments and Myosin in Skeletal Muscle Fibers. In Get Body Smart. Retrieved from http://www.getbodysmart.com/ap/muscletissue/fibers/thickfilaments/tutorial.html

    2 Structure and Function of Skeletal Muscle. Retrieved from http://courses.washington.edu/conj/motor/musclereview.htm


    You will also like...

    Water Cycle
    The Water Cycle

    The water cycle (also referred to as the hydrological cycle) is a system of continuous transfer of water from the air, s..

    Mātauranga Māori and Science Collaboration
    Mātauranga Māori and Science

    Mātauranga Māori is the living knowledge system of the indigenous people of New Zealand, including the relationships t..

    DNA molecule
    Genetic Control – On and Off Genes

    Genes are the blueprint of our bodies, a blueprint that creates a variety of proteins essential to any organism's surviv..

    Non-Mendelian Inheritance
    Non-Mendelian Inheritance

    In this tutorial, find out more about certain types of inheritance that does not follow the Mendelian inheritance patter..

    Hominid
    The Hominids

    The hominid family diversified from the apes around 6 to 8 million years ago. Since then, the evolutionary path has prov..

    Hormone Production
    Hormone Production

    Hormones are chemical messengers produced by specialized glands and they were produced by switching on the genes designe..