What is sarcolemma and sarcoplasm????
Answers
Answered by
1
Sarcoplasm is the cytoplasm of a myocyte(muscle fiber). It is comparable to the cytoplasm of other cells, but it contains unusually large amounts of glycosomes(granules of stored glycogen) and significant amounts of myoglobin, an oxygen-binding protein. The calcium ion concentration in sarcoplasma is also a special element of the muscle fiber; it is the means by which themuscle contractions take place and are regulated.
It contains mostly myofibrils (which are composed of sarcomeres), but its contents are otherwise comparable to those of the cytoplasm of other cells. It has a Golgi apparatus near the nucleus, mitochondria just inside the cell membrane (sarcolemma), and a smooth endoplasmic reticulum (specialized for muscle function and called thesarcoplasmic reticulum).
The sarcolemma (sarco (from sarx) from Greek; flesh, and lemma from Greek; sheath.) also called the myolemma, is the cell membrane of a striated muscle fiber cell.[1] It consists of a plasma membrane, which is alipid bilayer, and an outer coat consisting of a thin layer of polysaccharide material (glycocalyx) that contacts the basement membrane, which contains numerous thincollagen fibrils and specialized proteins such as laminin[2] that provide a scaffold for the muscle fiber to adhere to. Through transmembrane proteins residing in the plasma membrane, the actin skeleton inside the cell is connected to the basement membrane and the cell's exterior. At each end of the muscle fiber, the surface layer of the sarcolemma fuses with a tendon fiber, and the tendon fibers in turn collect into bundles to form the muscle tendons that then adhere onto bones.
The sarcolemma generally maintains the same function in muscle cells as the plasma membrane does in other eukaryote cells.[3] It acts as a barrier between the extracellular and intracellular compartments, defining the individual muscle fiber from its surroundings. The lipid nature of the membrane allows it to separate the fluids of the intra- and extracellular compartments, since it is only selectively permeable to water throughaquaporin channels. As in other cells this allows for the compositions of the compartments to be controlled by selective transport through the membrane. Membrane proteins, such as ion pumps, may create ion gradients with the consumption of ATP, that may later be used to drive transport of other substances through the membrane (Co-transport) or generate electrical impulses such as Action potentials.
It contains mostly myofibrils (which are composed of sarcomeres), but its contents are otherwise comparable to those of the cytoplasm of other cells. It has a Golgi apparatus near the nucleus, mitochondria just inside the cell membrane (sarcolemma), and a smooth endoplasmic reticulum (specialized for muscle function and called thesarcoplasmic reticulum).
The sarcolemma (sarco (from sarx) from Greek; flesh, and lemma from Greek; sheath.) also called the myolemma, is the cell membrane of a striated muscle fiber cell.[1] It consists of a plasma membrane, which is alipid bilayer, and an outer coat consisting of a thin layer of polysaccharide material (glycocalyx) that contacts the basement membrane, which contains numerous thincollagen fibrils and specialized proteins such as laminin[2] that provide a scaffold for the muscle fiber to adhere to. Through transmembrane proteins residing in the plasma membrane, the actin skeleton inside the cell is connected to the basement membrane and the cell's exterior. At each end of the muscle fiber, the surface layer of the sarcolemma fuses with a tendon fiber, and the tendon fibers in turn collect into bundles to form the muscle tendons that then adhere onto bones.
The sarcolemma generally maintains the same function in muscle cells as the plasma membrane does in other eukaryote cells.[3] It acts as a barrier between the extracellular and intracellular compartments, defining the individual muscle fiber from its surroundings. The lipid nature of the membrane allows it to separate the fluids of the intra- and extracellular compartments, since it is only selectively permeable to water throughaquaporin channels. As in other cells this allows for the compositions of the compartments to be controlled by selective transport through the membrane. Membrane proteins, such as ion pumps, may create ion gradients with the consumption of ATP, that may later be used to drive transport of other substances through the membrane (Co-transport) or generate electrical impulses such as Action potentials.
Similar questions