Acetylcholine (ACh) stimulates the contraction of skeletal muscle via nicotinic receptors and the contraction of smooth muscle via muscarinic receptors. Muscarinic receptors belong to the 7TM superfamily (seven transmembrane spanning superfamily) of G-protein linked receptors…
Download full paperFile format: .doc, available for editing
Download file to see previous pages
Here, ACh is the agonist of muscarinic receptors.
Mechanism of smooth muscle contraction – When ACh stimulates the G-protein coupled muscarinic receptors, a conformational change occurs, leading to the activation of the G-protein. The activated G-protein activates the intracellular enzyme, PLC (phospholipase C). This enzyme in turn hydrolyses PI(4,5)P2 (phosphatidylinositol-4,5-bisphosphate). This hydrolysis results in the production of two compounds – DAG (diacylglycerol) and IP3 (inositol-1,4,5-triphosphate). IP3 is soluble and diffuses through the cytosol. It binds to receptors on the endoplasmic reticulum resulting in the release of calcium ions (Ca2+) from the intracellular stores. The rise in intracellular calcium ions results in contraction of the smooth muscle. This happens when the intracellular calcium ions bind to calmodulin and activate it. Activation of calmodulin results in activation of the myosin light-chain kinase (MLCK) enzyme by the calcium-calmodulin complex, which then catalyzes the transfer of phosphate group from ATP to myosin cross bridges. The phosphorylated myosin cross bridges then interact with actin, causing shortening of the fiber. This results in muscle contraction. The cross-bridge cycle is powered by ATP.
Second messenger involved - IP3 (inositol-1,4,5-triphosphate) is the second messenger, as it relays the signal from outside the cell to the inside, resulting in the release of calcium ions that cause muscle contraction.
Acetylcholine (ACh) and adrenaline (Ad) are two agonists whose actions are independent of one another and result in opposite effects. Ad brings about the relaxation of pre-contracted smooth muscle by acting via the G-protein coupled β-adrenergic receptors on the cells.
Mechanism of Ad induced relaxation of pre-contracted smooth muscle – Ad binds to the G-protein linked β-adrenergic receptor causing a conformational change in the G-protein. This activates the enzyme adenylate cyclase.
...Download file to see next pagesRead More
(“Competitive Antagonism Essay Example | Topics and Well Written Essays - 500 words”, n.d.)
Competitive Antagonism Essay Example | Topics and Well Written Essays - 500 words. Retrieved from https://studentshare.org/biology/1586765-competitive-antagonism
(Competitive Antagonism Essay Example | Topics and Well Written Essays - 500 Words)
Competitive Antagonism Essay Example | Topics and Well Written Essays - 500 Words. https://studentshare.org/biology/1586765-competitive-antagonism.
“Competitive Antagonism Essay Example | Topics and Well Written Essays - 500 Words”, n.d. https://studentshare.org/biology/1586765-competitive-antagonism.
Therefore, the autonomic nervous system controls the involuntary activities of the smooth muscles and several undertakings o the glands. It forms a component of the peripheral nervous system and can be subdivided into two categories. These include the sympathetic and parasympathetic nervous system. In all these categories are comprised of effector neurons which connect the central nervous system top their effector organs.
Competitive Strategies. Chaos Camera Company Competitive Advantages.
This paper analyses the performance of our team in the simulation of a camera company. The company, Chaos Camera Company, was run as a team. The analysis is broken down into various parts: our competitive strategies, competitive advantage and actions of our competitors, our offensive and defensive strategic options, regional strategic approach, decisions supporting strategy execution, improving value chain activities, corporate social responsibility and finally our decision making style.
Therefore, the key aim of the paper is to study the competitive information associated with the vegetarian fast food concept promotion and development.
The key competitive issues for the Veggies are associated with
The three core competencies of an organization are innovativeness, quality, and effective customer service. These competencies are important because they create more value for customers and enhance improved customer satisfaction, leading to competitive advantage. They can be improved through training within the workplace.
The noncompetitive antagonism of a number of clinically useful drugs has been attributed to binding within the central lumen of the nAChRs. NCA activity has been routinely determined by measurement of concentration-dependent effects on whole-cell currents or nicotine-induced 86RB+ influx, yielding IC50 values.
The focus will be on the following four areas. The first task will be to identify the corporate logics (strategic action) that SABMiller have adopted over the course of the case. The second one will be an explanation of strategic position that
a known antagonist for muscarinic type cholinergic receptors, is tested against the known cholinergic agonist acetylcholine for potency and effectiveness. Acetylcholine is used alone and in combination with homatropine, both being used in varying concentrations, to test how
developments in the antibody antigen reactions that have seen to the development of clinical resistance to interventions against some parasites that has come up due to induced immunity as in the case of the malaria causing parasite.
A parasite is “an animal which lives on or
Price rise for year = 25% by British Gas. 7% increase 8 months ago + 18 and 16 percent raise now, prompting Energy Minister to press for change, inviting smaller and alternate energy suppliers to break dominance of big energy giants. BG
1 Pages(250 words)Essay
GOT A TRICKY QUESTION? RECEIVE AN ANSWER FROM STUDENTS LIKE YOU!
Save Your Time for More Important Things
Let us write or edit the essay on your topic
with a personal 20% discount.