It is in the mitochodria and speeds up the formation of ATP by breaking down ATP into ADP + energy. Muscle cells have many more mitochrondia than other cells.
An ATPase is a type of enzyme which converts adenosine triphosphate into adenosine diphosphate and a free phosphate ion.
Plasma Membrane
mitochondria
myosin head
During muscle contraction, myosin cross bridges attach to active sites of ACTIN FILAMENTS.
Acetylcholine (ah-Seh-til-KO-leen) is the organic molecule that triggers muscle contractions in humans. Acetylcholine acts on both the central nervous system (CNS) and on the peripheral nervous system (PNS). It is also the principal neurotransmitter in autonomic ganglia.
Muscle located beneath the frontalis and orbicularis oculi is called corrugator muscle. It draws the eyebrow down and wrinkles the forehead vertically.
Uponmuscle contraction, the A-bands do not change their length (1.85 micrometer in mammalian skeletal muscle) whereas the I-bands and the H-zone shorten.The protein tropomyosin covers the myosin binding sites of the actin molecules in the muscle cell. To allow the muscle cell to contract, tropomyosin must be moved to uncover the binding sites on the actin. Calcium ions bind with troponin-C molecules (which are dispersed throughout the tropomyosin protein) and alter the structure of the tropomyosin, forcing it to reveal the cross bridge binding site on the actin. The concentration of calcium within muscle cells is controlled by thesarcoplasmic reticulum, a unique form of endoplasmic reticulum. Muscle contraction ends when calcium ions are pumped back to the sarcomere. Once Calcium goes back into the sarcoplasmic reticulum, muscle relaxation starts.During stimulation of the muscle cell, themotor neuronreleases the neurotransmitter acetylcholine which travels across the neuromuscular junction (the synapse between the terminal bouton of the neuron and the muscle cell). Acetylcholine binds to a post-synaptic nicotinic acetylcholine receptor. A change in the receptor conformation allows an influx of sodium ions and initiation of a post-synaptic action potential. The action potential then travels along T (transverse) tubules until it reaches the sarcoplasmic reticulum; the action potential from the motor neuron changes the permeability of the sarcoplasmic reticulum, allowing the flow of calcium ions into the sarcomere. The outflow of calcium allows the myosin heads access to the actin cross bridge binding sites, permitting muscle contraction.Source(s):wikipedia "sarcomere"the sarcomere is the functional unit of the muscle cellutube "sarcomere" would give you a visual Do actin and myosin shorten during muscle contraction?
ATP is considered as the energy currency of cell or life. It store high energy needed to carry out bodily process such as metabolism of biomolecules, synthesis of proteins, lipids, carbohydrates., muscle contraction, transport of molecules across the cell membrane and so on. ATP is presenting in nucleus and cytoplasm of every single cell.
myosin
myosin
Myosin ATPase hydrolyze ATP into ADP+pi and yielding the energy required for muscle contraction.
Warm up exercises and ATPase activity of myosin determines the speed of muscle contraction. Studies with less warm up show muscle twitching.
myosin cross-bridges
"A muscle cell remains contracted until the release of acetylcholine stops and an enzyme produced at the axon terminal destroys any remaining acetylcholine."
Isometric contraction
SA node
constant contraction of a muscle is called the muscle tone
concentric contraction is atype of muscle contraction which the muscle shortens while genrating aforce The muscle shortens to produce movement. A muscle contraction in which shortening occurs.
type of contraction of gastrocnemius muscle?
6 steps in a muscle contraction