filamentous

Examples of filamentous in the following topics:

• Sliding Filament Model of Contraction

  • In the sliding filament model, the thick and thin filaments pass each other, shortening the sarcomere.
  • The sliding filament theory describes the process used by muscles to contract.
  • To understand the sliding filament model and understanding of sarcomere structure is first required.
  • An alternative description is the region spanned by the titin molecule connecting the Z-line with a myosin filament.
  • At the level of the sliding filament model expansion and contraction only occurs within the I and H-bands, the myofilaments themselves do not contract or expand and so the A-band remains constant.

• Intermediate Filaments and Microtubules

  • Microtubules, along with microfilaments and intermediate filaments, come under the class of organelles known as the cytoskeleton.
  • Intermediate filaments (IFs) are cytoskeletal components found in animal cells.
  • Intermediate filaments contribute to cellular structural elements and are often crucial in holding together tissues like skin .
  • Keratin cytoskeletal intermediate filaments are concentrated around the edge of the cells and merge into the surface membrane.
  • This network of intermediate filaments from cell to cell holds together tissues like skin.

• Skeletal Muscle Fibers

  • Within the sarcomere actin and myosin myofilaments are interlaced with each other and via the sliding filament model of contraction slide over each other.
  • There are two main types of filaments: thick filaments and thin filaments.
  • Thick filaments occur are composed predominately of myosin proteins, the tails of which bind together leaving the heads exposed to the interlaced thin filaments.
  • Thin filaments are composed predominately of actin, tropomyosin, and troponin.
  • The sarcomere is the functional contractile region of the myocyte, and defines the region of interaction between a set of thick and thin filaments.

• Control of Muscle Tension

  • Cross-bridges can only form where thick and thin filaments overlap, allowing myosin to bind to actin.
  • Maximal tension occurs when thick and thin filaments overlap to the greatest degree within a sarcomere.
  • If a sarcomere at rest is stretched past an ideal resting length, thick and thin filaments do not overlap to the greatest degree so fewer cross-bridges can form.
  • As a sarcomere shortens, the zone of overlap reduces as the thin filaments reach the H zone, which is composed of myosin tails.
  • Conversely, if the sarcomere is stretched to the point at which thick and thin filaments do not overlap at all, no cross-bridges are formed and no tension is produced.

• Microfilaments

  • There are three types of fibers within the cytoskeleton: microfilaments, intermediate filaments, and microtubules.
  • For this reason, microfilaments are also known as actin filaments.
  • Actin is powered by ATP to assemble its filamentous form, which serves as a track for the movement of a motor protein called myosin.
  • When your actin and myosin filaments slide past each other, your muscles contract.

• Angiosperm Flowers

  • Stamens are composed of a thin stalk called a filament and a sac-like structure called the anther.
  • The filament supports the anther, where the microspores are produced by meiosis and develop into pollen grains .

• Viral Morphology

  • In general, the shapes of viruses are classified into four groups: filamentous, isometric (or icosahedral), enveloped, and head and tail.
  • Filamentous viruses are long and cylindrical.
  • Many plant viruses are filamentous, including TMV (tobacco mosaic virus).
  • They have a head that is similar to icosahedral viruses and a tail shape like filamentous viruses.

• Intercellular Junctions

  • Short proteins called cadherins in the plasma membrane connect to intermediate filaments to create desmosomes.
  • It is created by the linkage of cadherins and intermediate filaments.

• The Mitotic Phase and the G0 Phase

  • A contractile ring composed of actin filaments forms just inside the plasma membrane at the former metaphase plate.
  • The actin filaments pull the equator of the cell inward, forming a fissure.
  • During cytokinesis in animal cells, a ring of actin filaments forms at the metaphase plate.

• ATP and Muscle Contraction

  • As myosin expends the energy, it moves through the "power stroke," pulling the actin filament toward the M-line.