Help me pls?

Question

Can someone pls explain to me what a sacromere is and what its function is.

Answer 1

Sacromere? Whats that??

Answer 2

it is any of the segments of myofibril in striated muscel fiber.
A sarcomere is the basic unit of a cross striated muscle's myofibril. Sarcomeres are multi-protein complexes composed of three different filament systems. The thick filament system is composed of myosin protein, the thin filaments are assembled by actin monomers and the elastic filament system is composed of the giant protein titin (also called connectin). A muscle cell, from a bicep, may contain 100,000 sarcomeres. The myofibrils of smooth muscle cells are not arranged into sarcomeres.

The sarcomeres are what give skeletal and cardiac muscles their striated appearance. A sarcomere is defined as the segment between two neighbouring Z-lines (or Z-discs). In electron micrographs of cross striated muscle the Z-line appears as a series of dark lines. Surrounding the Z-disc is the region of the I-band. Following the I-band is the A-band. Within the A-band is a paler region called the H-band. Finally, inside the H-band is a thin M-line (or M-band). A-bands and I-bands were named after anisotropic and isotropic, respectively; their properties under a polarizing microscope. Actin filaments are the major component of the I-band and extend into the A-band. Myosin filaments extend throughout the A-band and are thought to overlap in the M-band. The giant protein titin (connectin) extends from the Z-disc of the sarcomere, where it binds to the thin filament system, to the M-band, where it is thought to interact with the thick filaments. The Titin protein (and its splice isoforms) is the biggest single protein found in nature. It provides binding sites for numerous proteins and is thought to play an important role as sarcomeric ruler and as blueprint for the assembly of the sarcomere. Several proteins important for the stability of the sarcomeric structure are found in the Z-disc as well as in the M-band of the sarcomere. Actin filaments and Titin molecules are cross-linked in the Z-disc via the Z-disc protein alpha-Actinin. The M-band proteins Myomesin as well as M-protein crosslink the thick filament system (Myosins) and the M-band part of Titin (the elastic filaments). The interaction between actin and myosin filaments in the A-band of the sarcomere is responsible for the muscle contraction (sliding filament model).

Answer 3

The sacromere allows for muscle contraction. During a contraction, myosin and actin filaments interact to shorten the sacromere length. Both contracting and relaxing of muscles requires energy found in ATP. Muscles are also heavily dependent on calcium for energy to contract. The force of a muscle contraction is determined by the number of muscle fibers that are stimulated.

Adenosine 5'-triphosphate (ATP) is a multifunctional nucleotide that is most important as a "molecular currency" of intracellular energy transfer. In this role, ATP transports chemical energy within cells for metabolism. It is produced as an energy source during the processes of photosynthesis and cellular respiration and consumed by many enzymes and a multitude of cellular processes including biosynthetic reactions, motility and cell division. In signal transduction pathways, ATP is used as a substrate by kinases that phosphorylate proteins and lipids, as well as by adenylate cyclase, which uses ATP to produce the second messenger molecule cyclic AMP.

The structure of this molecule consists of a purine base (adenine) attached to the 1' carbon atom of a pentose sugar (ribose). Three phosphate groups are attached at the 5' carbon atom of the pentose sugar. ATP is also incorporated into nucleic acids by polymerases in the processes of DNA replication and transcription. When ATP is used in DNA synthesis, the ribose sugar is first converted to deoxyribose by ribonucleotide reductase.

Answer 4

The sarcomeres are what give skeletal and cardiac muscles their striated appearance.

"Sarcomeres are the functional unit of striated muscle (skeletal & cardiac). It is a series of sub-units, divided by Z lines, and is found in the myofibrils of muscle...." The source website has a big section on the function of them.

Answer 5

a *sarcomere* is a "basic unit of a muscle's cross-striated myofibril. Sarcomeres are multi-protein complexes composed of three different filament systems."

im pretty sure it helps the muscle contract and such, but dont take my word for it. Ask Reading Rainbow...dfjdfkdsf...i mean... Go to Source. :D

Answer 6

a sarcomere is a basic contractile unit of muscle, this helps digest the nutrients in ur body

Answer 7

The answer is musles and their response to stimulus, check it out on the web for all the info on this topic.
Later, Doc

Answer 8

it is the contractile unit of striated muscle. and it function is stored up energy

Answer 9

http://en.wikipedia.org/wiki/Sarcomere