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Sarcomere think filaments are linked laterally by proteins of the?
z line
What are the outer boundaries of the sarcomere?
The outer boundaries of the sarcomere are defined by the Z-discs or Z-lines, which mark the ends of the sarcomere unit. These Z-discs separate one sarcomere from the next and provide attachment points for actin filaments.
The region between two successive Z discs is called?
Sarcomere
What is atrial depolarization?
Atrial depolarization is the first part of the cardiac cycle.Cardiac (and skeletal) muscle is made up of bundled stands of functional units called sarcomeres. Each sarcomere consists of two Z-disks, which mark the ends of each sarcomere, and alternating dark and light bands called A-bands and I-bands respectively. The I-band contains only actin (the main cytoskeletal protein in most cells) filaments whereas the A-band contains overlapping myosin (a "molecular motor" protein) and actin filaments in its periphery and only myosin filaments in the central region called the H-zone. The center of the H-zone is marked by an imaginary line (called the M-line) in which myosin extends in both directions. The sarcomere contracts inward toward the M-line. "Depolarization" occurs when an electrochemical event causes calcium cations to be released from a membranous network (similar to the the endoplasmic reticulum) called the sarcoplasmic reticulum and creates an action potential. The free Ca2+ binds to a specific troponin protein shifting a troponin/tropomyosin protein complex allowing the myosin head groups to bind to the actin filament. ATP hydrolysis causes conformational changes of the myosin filament which in effect "pulls" the actin filament toward the M-line of the sarcomere. The sarcomere can return to its resting potential by allowing potassium (K+) ions to flow out.
The sarcomere is defined as the space between two?
One of the segments into which a fibril of striate
In skeletal muscle where is the z-line?
Actin molecules are bound to the Z line, which forms the borders of the sarcomere. Other bands appear when the sarcomere is relaxed. The Z line is found between two sarcomeres.
End of a sarcomere is marked by?
z disc
The segment of a myofibril that is called a sarcomere runs from?
One Z line to the next Z line
Sarcomere think filaments are linked laterally by proteins of the?
z line
Are sarcomere thick filaments linked laterally by proteins of the Z line?
No, the M line
The basic unit of muscle contraction is the sarcomere which is?
the distance from one Z line to the next
A sarcomere is?
A sarcomere consists of thin and thick filaments arranged so they can slide over each other. The boundary of the sarcomere are the Z lines. Thin filaments extend from the Z lines and overlap with thick filaments in the middle of the sarcomere. The I band is on each side of the Z line where only thin filaments occur. The A band is the length of the thick filaments and is divided into three parts; the zone of overlap is on each end where thin and thick filaments occur, the H band is in the middle and has only thick filaments, and the M line is the center of the A band.
What are the outer boundaries of the sarcomere?
The outer boundaries of the sarcomere are defined by the Z-discs or Z-lines, which mark the ends of the sarcomere unit. These Z-discs separate one sarcomere from the next and provide attachment points for actin filaments.
What defines a sarcomere?
A sarcomere is the basic unit of a striated muscle. In humans, each muscle is composed of multiple bundles of muscle fibers or cells. Each fiber is comprised of myofibrils. In between sarcomeres lies the z line or the z disc. When strained, the z line appears dark with a distinct border. In the z lines, thin filaments reach toward the center, and overlap. These filaments all represent the structures of the sarcomeres.
What is the regions of a muscle fiber separated by Z discs?
sarcomere
What is sarcomere?
area in the muscle between the two Z discs.
What region in a sarcomere does actin and myosin overlap?
z disc
