What role does acetylcholinesterase play in muscle contraction?

When a motor nerve cell gets the proper signal from the nervous system, it releases acetylcholine into its synapses with muscle cells. There, acetylcholine opens receptors on the muscle cells, triggering the process of contraction.

How are acetylcholine calcium and ATP involved in contraction?

Muscle contraction ends when calcium ions are pumped back into the sarcoplasmic reticulum, allowing the muscle cell to relax. During stimulation of the muscle cell, the motor neuron releases the neurotransmitter acetylcholine, which then binds to a post-synaptic nicotinic acetylcholine receptor.

What is the function of acetylcholinesterase?

The enzyme acetylcholinesterase (AChE) is a serine hydrolase whose primary function is to degrade acetylcholine (ACh) and terminate neurotransmission. Apart from its role in synaptic transmission, AChE has several “non-classical” functions in non-neuronal cells.

Does acetylcholinesterase increase muscle contraction?

An enzyme called acetylcholinesterase breaks down acetylcholine. Some drugs that are used to treat myasthenia gravis act on acetylcholinesterase to stop the breakdown of acetylcholine. These acetylcholinesterase inhibitors increase the amount of acetylcholine available and so help muscle activation and contraction.

Is ATP required for muscle relaxation?

ATP is required for both muscle contraction and muscle relaxation.

Which of the major proteins involved in muscle contraction hydrolyzes ATP?

Myosin binds to actin at a binding site on the globular actin protein. Myosin has another binding site for ATP at which enzymatic activity hydrolyzes ATP to ADP, releasing an inorganic phosphate molecule and energy. ATP binding causes myosin to release actin, allowing actin and myosin to detach from each other.

What is the role of acetylcholinesterase quizlet?

What is the function of acetylcholinesterase? This enzyme breaks down acetylcholine and prevents the generation of multiple action potentials from a single nerve impulse.

How would a lack of acetylcholinesterase impact the muscle contraction process?

muscle contractions broken down by the enzyme acetylcholinesterase, which is anchored in the basement membrane, or diffuses out of the primary cleft, thus preventing constant stimulation of acetylcholine receptors.

What effect would inhibition of acetylcholinesterase have on muscle tissue and why?

Acetylcholinesterase (AChE) inhibitors, including PB, produce acute destructive changes at the neuromuscular junction, the site of connection between nerve cells and muscle fibers, at which nerve cells signal muscles to contract.

How are calcium and ATP used to assist with muscle actions?

How are calcium and ATP used to assist with muscle actions? Calcium binds to troponin, causing a shift in tropomyosin. The myosin cross-bridge head is now able to attach to the actin filament, allowing cross-bridge flexion to occur. Calcium ions must remain available for continued muscle action.

What is the function of acetylcholinesterase and where is it found quizlet?

Acetylcholinesterase (AChE) which breaks down acetylcholine into choline and acetic acid. – Found in the presynaptic cell, where it can metabolize excess ACh that may have been synthesized. – Present in the membrane of the postsynaptic cell to break down molecules of ACh after their release into the synaptic cleft.

Which method of regenerating ATP during muscle contraction produce lactic acid?

Glycolysis converts glucose to pyruvate, water and NADH, producing two molecules of ATP. Excess pyruvate is converted to lactic acid which causes muscle fatigue.

What is acetylcholinesterase secreted by muscle?

Acetylcholinesterase is secreted by the muscle and remains attached to it by collagen fastened to the basal lamina. ACh molecules that do not bind immediately with a receptor or those released after reacting with a receptor are hydrolyzed almost instantly (in less than 1 msec) by acetylcholinesterase.

How does acetylcholine affect muscle contraction?

It also affects the contraction of smooth and cardiac muscle. Acetylcholine is held in synaptic vesicles in nerve terminals until an electrical signal causes its release onto a specialized portion of a muscle cell membrane equipped with receptors that recognize the neurotransmitter.

How do acetylcholinesterase inhibitors work?

Acetylcholinesterase (AChE) inhibitors work by preventing the breakdown of acetylcholine in the synaptic cleft, resulting in more acetylcholine availability for neurotransmission. Donepezil was the first acetylcholinesterase inhibitor to be licensed in the UK, in 1997.

Why is acetylcholinesterase a weak point in the body?

Attacking Acetylcholinesterase. Since acetylcholinesterase has an essential function, it is a potential weak point in our nervous system. Poisons and toxins that attack the enzyme cause acetylcholine to accumulate in the nerve synapse, paralyzing the muscle.