filamentous

Examples of filamentous in the following topics:

• Bacterial Differentiation

  • In bacteria, the transformation into filamentous organisms have been recently demonstrated.
  • Filamentous bacteria have been considered to be over-stressed, sick and dying members of the population.
  • However, the filamentous members of some communities have vital roles in the population's continued existence, since the filamentous phenotype can confer protection against lethal environments.Filamentous E. coli can be up to 70 µm in length and has been identified as playing an important role in pathogenesis in human cystitis.
  • Since the filament can increase a cell's uptake–proficiency surface without changing its surface-to-volume ratio appreciably, this may be enough reason for cells to be filament.
  • In addition, the filamentation may allow bacterial cells to access nutrients by enhancing the possibility that the filament will be exposed to a nutrient-rich zone and pass compounds to the rest of the cell's biomass.

• 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.

• Mechanism and Contraction Events of Cardiac Muscle Fibers

  • The actual mechanical contraction response in cardiac muscle occurs via the sliding filament model of contraction.
  • In the sliding filament model, myosin filaments slide along actin filaments to shorten or lengthen the muscle fiber for contraction and relaxation.
  • The myosin head binds to ATP and pulls the actin filaments toward the center of the sarcomere, contracting the muscle.
  • Intracellular calcium is then removed by the sarcoplasmic reticulum, dropping intracellular calcium concentration, returning the troponin complex to its inhibiting position on the active site of actin, and effectively ending contraction as the actin filaments return to their initial position, relaxing the muscle.
  • This animation shows myosin filaments (red) sliding along the actin filaments (pink) to contract a muscle cell.

• 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.

• Fts Proteins and Cell Division

  • FtsZ has been named after "Filamenting temperature-sensitive mutant Z".
  • The Z-ring forms from smaller subunits of FtsZ filaments.
  • These filaments may pull on each other and tighten to divide the cell.
  • The Z-ring forms from smaller subunits of FtsZ filaments.
  • These filaments may pull on each other and tighten to divide the cell.

• 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.

• Rigor Mortis

  • Diffusion of the calcium through the pumps occurs, facilitation binding of myosin and actin filaments.
  • This cycle of the sliding filament mechanism cannot be completed, so muscles maintain ridigity until enzymatic degradation of muscle fibers.
  • Diagram showing Actin-Myosin filaments in Smooth muscle.

• 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.

• Elastic Arteries

  • An elastic artery or conducting artery is an artery with a large number of collagen and elastin filaments in the tunica media.
  • Elastic arteries contain larger numbers of collagen and elastin filaments in their tunica media compared to muscular arteries giving them ability to stretch in response to each pulse.
  • Due to position as the first part of the systemic circulatory system, and thus the high pressures it will experience immediately adjacent to the heart the aorta is perhaps the most elastic artery and features an incredibly thick tunica media rich in elastic filaments.