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Both do have actin and myosin.
Within each skeletal muscle fiber are hundreds of lengthwise subdivisions called myofibrils.
Myofibrils are made up of bundles of the protein filaments (myofilaments) that are responsible for muscle contraction: thin filaments: made of the protein actin, and
thick filaments: made of the protein myosin.
These are visible using a microscope.
The internal organization of actin and myosin in smooth muscle is different from that in the striated muscles.
Smooth muscle cells: are long and slender, are spindle shaped, with a single, central nucleus, have scattered myosin fibers, with more heads per thick filament and have actin filaments attached to dense bodies.
These can not be seen using a microscope and that is why they are also called smooth muscle fibers.
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How does a lack of calcium reuptake to the sacroplasmic reticulum affect the muscle?
The thin filament sites remain open to the binding and stroke of the thick filament and there would be no muscle relaxation without the reuptake of Ca 2+ so the thin filament sites are closed.
What filament is connected to the Z line thick or thin?
thin
How are proteins organized in sarcomere?
Thick and thin filaments that slide past each other when a muscle contracts.
Which of the following become connected by myosin cross-bridges during muscle contraction A) thin filaments and thick filaments B) thin filaments and t-tubules C) thick filaments and titin filame?
Interactions between actin and myosin filaments of the sarcomere are responsible for muscle contractions. The I bands contain only thin (actin) filaments, whereas the A bands contain thick (myosin) filaments.
What is the difference between a thin and thick atmosphere?
A thin atmosphere is thin and a thick atmosphere is thick
Are there more thick filaments than thin filaments in smooth muscle?
There more thin filaments than thick filaments in smooth muscle. The ratio is of the thin to thick filaments in the smooth muscle is approximately 15:1.
How does a lack of calcium reuptake to the sacroplasmic reticulum affect the muscle?
The thin filament sites remain open to the binding and stroke of the thick filament and there would be no muscle relaxation without the reuptake of Ca 2+ so the thin filament sites are closed.
What filament is connected to the Z line thick or thin?
thin
The thin filaments of a sarcomere consist of?
The length of the thick filament is the A band. The A band contains both thick and thin filament because they are overlapping each other. The H band is thick filament only, however, it only covers a portion of width of the thick filament.
What happens when thin filaments in a muscles fiber slide over the thick filament?
Contraction or relaxation of muscle fibre, due to similar effect in sarcomere
What chemical ion is responsible for initiating the contraction of a muscle fiber?
Calcium ions bind to the thin filament ( actin ), turn it and expose the binding site to the thick filament (myosin ).
How can smooth muscle contract if it has no striation or sarcomeres?
Actin and myosin are present in all three muscle types. In skeletal and cardiac muscle cells, these proteins are organized in sarcomeres, with thin and thick filaments. The internal organization of a smooth muscle cell is very different: • A smooth muscle fibre has no T tubules, and the sarcoplasmic reticulum (SR) forms a loose network throughout the sarcoplasm. Smooth muscle tissue has no myofibrils or sarcomeres. As a result, this tissue also has no striations and is called nonstriated muscle. • Thick filaments are scattered throughout the sarcoplasm of a smooth muscle cell. The myosin proteins are organized differently than in skeletal or cardiac muscle cells, and smooth muscle cells have more cross-bridges per thick filament. • The thin filaments in a smooth muscle cell are attached to dense bodies, structures distributed throughout the sarcoplasm in a network of intermediate filaments composed of the protein desmin. Some of the dense bodies are firmly attached to the sarcolemma. The dense bodies and intermediate filaments anchor the thin filaments such that, when sliding occurs between thin and thick filaments, the cell shortens. Dense bodies are not arranged in straight lines, so when a contraction occurs, the muscle cell twists like a corkscrew. • Adjacent smooth muscle cells are bound together at dense bodies, transmitting the contractile forces from cell to cell throughout the tissue. • Although smooth muscle cells are surrounded by connective tissue, the collagen fibres never unite to form tendons or aponeuroses as they do in skeletal muscles.
Sentence with filament?
Filament was made from plastic. The filament was very stable and smooth.
How does a muscle contact according to the sliding-filament model of muscle contraction?
When skeletal (or cardiac) muscle contracts, the thin and thick filaments in each sarcomereslide along each other without their shortening, thickening, or folding.
What are the two types of myofilaments?
The two filaments involved are myosin and actin. Actin: is the framework and slides over the myosin filament when the muscle is shortened. myosin: is a thick filament Also a sacromere: is made up of the actin and myosin. It is the functional unit of a muscle fibre and extends from z line to z line. A muscle contraction: is many sacromeres shortening ( actin sliding over myosin)
Does a lamp with a thick filament draw more current or less current than a lamp with a thin filament?
A lamp with a thick filament will draw more current. What restricts the current flow in the filament is the resistance of the filament which increases as the temperature of the filament increases. A thin filament requires less energy to get heated up that a thick one so less current to achieve threshold resistance. Also a thick filament provides a broader path for current so there is less resistance per increase in degree centigrade. For these two (closely related but distinct) reasons it will require more current for the filament to get heated up to threshold resistance.
How does a muscle contract according to the sliding-filament model of muscles contraction?
When skeletal (or cardiac) muscle contracts, the thin and thick filaments in each sarcomereslide along each other without their shortening, thickening, or folding.
