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Acetylcholine is a choline molecule that has been acetylated at the oxygen atom. Because of the charged ammonium group, acetylcholine does not penetrate lipid membranes. . Because of this, when the molecule is introduced externally, it remains in the extracellular space and at present it is considered that the molecule does not pass through the blood–brain
Although humans synthesize choline in the liver, the amount produced naturally is insufficient to meet cellular functions, requiring that some choline be obtained from foods or dietary supplements. [3] Foods rich in choline include meats, poultry, eggs, and other animal-based products, cruciferous vegetables, beans, nuts, and whole grains. [3]
Choline acetyltransferase was first described by David Nachmansohn and A. L. Machado in 1943. [6] A German biochemist, Nachmansohn had been studying the process of nerve impulse conduction and utilization of energy-yielding chemical reactions in cells, expanding upon the works of Nobel laureates Otto Warburg and Otto Meyerhof on fermentation, glycolysis, and muscle contraction.
It is produced during the breakdown of glucose, fatty acids, and amino acids, and is used in the synthesis of many other biomolecules, including cholesterol, fatty acids, and ketone bodies. Acetyl-CoA is also a key molecule in the citric acid cycle , which is a series of chemical reactions that occur in the mitochondria of cells and is ...
The enzyme acetylcholine esterase breaks down the neurotransmitter acetylcholine, which is released at nerve and muscle junctions, in order to allow the muscle or organ to relax. The result of acetylcholine esterase inhibition is that acetylcholine builds up and continues to act so that any nerve impulses are continually transmitted and muscle ...
Adrenaline was first synthesized in the laboratory by Friedrich Stolz and Henry Drysdale Dakin, independently, in 1904. [ 97 ] Although secretin is mentioned as the first hormone, adrenaline is the first hormone since the discovery of the activity of adrenal extract on blood pressure was observed in 1895 before that of secretin in 1902. [ 72 ]
The remaining 5–10% of the succinylcholine dose acts as an acetylcholine receptor agonist at the neuromuscular junction, causing prolonged depolarization of the postsynaptic junction of the motor-end plate. This depolarization initially triggers fasciculation of skeletal muscle. As a result of prolonged depolarization, endogenous ...
Acetylcholinesterase (HGNC symbol ACHE; EC 3.1.1.7; systematic name acetylcholine acetylhydrolase), also known as AChE, AChase or acetylhydrolase, is the primary cholinesterase in the body. It is an enzyme that catalyzes the breakdown of acetylcholine and some other choline esters that function as neurotransmitters :