Myosin
Myosin is one of the protein molecules that (together with tropomyosin, troponin, and actin) forms the cylindrical structures called myofibrils that, together, form muscle fibers.
Myofibrils consist of two types of protein filaments, called thin filaments, and thick filaments. Myosin molecules, form the thick filaments, whose structure is illustrated below (lower image).
Above: Diagram of a single myosin molecule
Above: Diagram of a Thick Filament
There are approx. 200 myosin molecules forming a typical thick
filament. These molecules are arranged with their "tails" parallel to
each other as illustrated above.
Myosin molecules are important for the process of muscle contraction. The myosin "heads" or "crossbridges" are attached to "myosin-binding sites" on positions on another protein called actin, which is located in the thin filaments of the myofibrils.
This section consists of short summaries about the
structures that form the muscles of the body.
This list is not exhaustive but is intended to be appropriate for students
of A-Level Human Biology, ITEC courses in massage and related subjects,
and other courses in health sciences. For more general information about muscles see
the pages about:
This section is about the
anatomical structures of muscles.
- Anterior Muscles
- Posterior Muscles
- Facial Muscles
- Muscle Terminology (Definitions)
- 1. Structure of Muscle
- 2. Structure of Muscle Cells
- 3. Muscle Filaments
- 4. Sliding Filament Theory
- 5. Neuromuscular Junction
- 6. Actions at Neuromuscular Junction
- Types of Muscle Contractions
- Muscular Disorders
- Effects of exercise on muscles
