Week 3 ion channel —3 Peer Response 800w. due9-20-23
Instructions:
Please read and respond to the two peers' initial postings for week 2 below. Consider the following questions in your responses.
Compare and contrast your initial posting with those of your peers.
1. How are they similar or how are they different?
2. What information can you add that would help support the responses of your peers?
3. Ask your peers a question for clarification about their post.
4. What most interests you about their responses?
5. Summaries at least 1 evidence based article that supports there point.
Please be sure to validate your opinions and ideas with citations and references in APA format.
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Response 1 400 words
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Week 3 Discussion: Ion Channels
Compare and contrast the two different major classes of ion channels.
The two different major classes of ion channels are ligand-gated ion channels and voltage-gated ion channels, both of which are membrane proteins that play a vital role in regulating cell membrane potential and neuron communication (Stahl, 2021). Ligand-gated ion channels are also referred to as ionotropic receptors, this is because LGIC is both a receptor and channel and thus serves a dual function (Stahl, 2021). LGIC are made of amino acids and contain multiple binding sites to bind ligands such as neurotransmitters, ions, and drugs, allowing ions to either bind to a receptor or travel through the channel (Stahl, 2021). Voltage-gated ion channels are channels that mediate nerve conduction, action potential, and neurotransmitter release (Stahl, 2021). These channels are controlled by the change in ionic charge or voltage across the cell membrane (Stahl, 2021). Voltage-gated ion channels tend to be more selective, allowing the influx of only one ion at a time, whereas ligand-gated channels are less selective in nature and allow different types of ions to pass through the channel (Alberts, 2002).
Explain the difference between full agonists, partial agonists, antagonists, and inverse agonists.
An agonist is a ligand that binds to a receptor changing its state to result in a response (Stahl, 2021). The difference between full agonist, partial agonist, antagonist, and inverse agonist is that a full agonist leads to maximum signal transduction, whereas a partial agonist does not reach maximum signal transduction even with full receptor occupancy and can act as an antagonist in the presence of a full agonist (Stahl, 2021). Antagonists, on the other hand, is a ligand that binds to a receptor inhibiting its agonist-stimulated response (Stahl, 2021). Inverse agonists are ligands that when binding to a receptor cause a decrease in signal transduction, thus, their effect is the opposite of an agonist (Stahl, 2021).
References
Alberts, B. (2002). Ion channels and the electrical properties of membranes. Molecular Biology of the Cell – NCBI Bookshelf. https://www.ncbi.nlm.nih.gov/books/NBK26910/
Stahl, S. M. (2021). Stahl’s Essential Psychopharmacology. https://doi.org/10.1017/9781108975292
Response 2. 400 words
1.
Compare and contrast the two different major classes of ion channels.
To start this discussion board I would like to define what are ion channels. Ion channels are membrane proteins, which play a major role in regulating cellular excitability. There are 3 major ion channels but for this homework assignment, I will compare and contrast voltage-gated ion channels and Ligand-Gated Ion Channels (LGIC).
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Ligand-gated ion channels open when a chemical ligand such as a neurotransmitter binds to the protein (Libretexts, 2023).
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Voltage channels open and close in response to changes in membrane potential (Libretexts, 2023). Ion channels can be classified by how they respond to the environment.
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Ligand-gated ion channel’s permeability is greatly increased when some type of chemical ligand binds to the protein structure (Libretexts, 2023)
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Voltage-gated channels respond to disturbances in cell membrane potential and are highly selective for specific ions such as sodium, potassium, calcium, and chloride (Ratan, 2018).
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Explain the difference between full agonists, partial agonists, antagonists, and inverse agonists.
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A molecule or chemical compound that can bind to a receptor and activate the receptor therefore causing a biological response (Agonist, partial agonist, antagonist, inverse agonist, 2019) |
A molecule or chemical compound that can bind to a receptor and “weakly activate the receptor below maximum response (Agonist, partial agonist, antagonist, inverse agonist, 2019) |
A molecule or chemical compound that binds to the receptor but does not cause any activation in the receptor, therefore not causing any biological response (Agonist, partial agonist, antagonist, inverse agonist, 2019) |
Molecule of chemical compound that can bind to a receptor leading to deactivation, and decreasing the baseline activity of the receptor (Agonist, partial agonist, antagonist, inverse agonist, 2019) |
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References:
Agonist, partial agonist, antagonist, inverse agonist. PharmaEducation. (2023, August 11). https://pharmaeducation.net/agonist-partial-agonist-antagonist-inverse-agonist/
Libretexts. (2023, January 17). 10.5b: Ion Channels. Medicine LibreTexts. https://med.libretexts.org/Bookshelves/Anatomy_and_Physiology/Anatomy_and_Physiology_(Boundless)/10%3A_Overview_of_the_Nervous_System/10.5%3A_Neurophysiology/10.5B%3A_Ion_Channels
Ratan , N. (2018, October 26). Types of ion channels in the body. News. https://www.news-medical.net/health/Types-of-Ion-Channels-