What is the relationship of pharmacodynamics & osmosis?
Ans)
Pharmacodynamics refers to the mechanisms and effects of medications within the body. Or more simply, it’s what medications do to the body and how they do it.
Alright, so, in order to have an effect, most medications have to reach their target cells and bind to a receptor.
Receptors are specialized proteins both on the cell membrane and inside the cell, that can bind to a ligand and get triggered to alter their shape or activity.
This gives rise to a signal cascade of intracellular molecules - the second messengers, which, ultimately, results in some change in the cell’s function.
Intracellular receptors are typically located in the cytoplasm or nucleus of the cell and recognize small, hydrophobic, meaning water- hating, ligands. These include molecules like steroids, which are happy to diffuse across the phospholipid membrane.
Once bound to their ligand, the receptor- ligand complex attaches to specific DNA sequences that activate or inhibit specific genes.
On the cell membrane are cell-surface receptors, which are embedded into the plasma membrane and bind to ligands too large or hydrophilic, meaning water- loving, to pass through.
Based on their structure and properties, cell- surface receptors fall into three main types.
First are ligand- gated ion channels, which form channels or pores that are generally closed, but then open up once they bind a specific ligand.
They allow ions like chloride, calcium, sodium, and potassium to passively flow into the cell, down their gradient, and trigger the signaling pathway.
Next are the G- protein coupled receptors, also known as seven- pass transmembrane receptors, which means they are really long proteins that have one end that sits outside the cell, and then the snake- like protein dips in and out of the cell membrane seven times, and finally ends on the inside of the cell.
The ligand binds to the end sitting outside the cell, and the end of the protein that’s within the cell activates guanine nucleotide-binding proteins or G proteins, which contain an alpha, beta, and gamma subunit.
Normally, the alpha subunit binds to a guanosine diphosphate or GDP molecule and the G protein is inactive.
When a ligand binds to the receptor, the G protein changes shape, causing the alpha subunit to release the GDP and allowing a guanosine triphosphate or GTP, to bind. This causes the alpha subunit to detach and trigger other proteins in the signalling pathway.
Broadly speaking, there are three types of G proteins: Gq, Gi, and Gs. Each type has its own kind of alpha subunit.
The Gq protein activates the enzyme phospholipase C, which cleaves a phospholipid called phosphatidylinositol 4,5-bisphosphate into inositol trisphosphate and diacylglycerol.
On the other hand, protein Gs and Gi stimulate or inhibit, respectively, the enzyme adenylate cyclase, which takes adenosine triphosphate or ATP, and removes two phosphate molecules and transforms it into cyclic adenosine monophosphate or cAMP.
Inositol trisphosphate, diacylglycerol and cAMP then go on stimulate and inhibit different sets of enzymes and molecular pathways.
Finally, there are the enzyme-coupled receptors. These are usually single- pass transmembrane proteins, meaning that they have only one transmembrane segment.
The extracellular end of these receptors binds to ligands, and their intracellular end has enzyme activity.
The enzymatic domain is usually a protein kinase which phosphorylates other molecules.
When a ligand binds, it triggers a conformational change in the enzymatic domain to form high-affinity binding sites for secondary messenger.
What is pharmacodynamics? what is the relationship to osmosis? Ion charges? Lipids?
Relating to pharmacology: What is pharmacodynamics? what is the relationship to osmosis? Ion charges? Lipids?
what is the relationship between pharmacodynamics & ions? what is the relationship between pharmacodynamics & ion charges?
what is the relationship between pharmacodynamics & lipids?
Anorexiants-pharmacodynamics and pharmacotherapeutics (esp. precautions and clinical uses and dosing) Anticonvulsants pharmacodynamics and pharmacotherapeutics (specifically the adverse drug reactions rational selection of the major types) Antidepressants-pharmacodynamics, pharmacokinetics, metabolism and excretion, and pharmacotherapeutics (precautions and contraindications, adverse reactions and clinical uses in the following- TCAS, MAOIS, SSRIS, SNRIIS. How long should it be before patient sees improvement and be familiar with their use in children) Antipsychotics- pharmacodynamics and pharmacotherapeutics Antianxiety and hypnotics-pharmacodynamics and pharmacotherapeutics (pages 267-271). Look at issues of dependence...
Alpha2 Agonists: Central -pharmacodynamics and pharmacotherapeutics (mainly look at Clonidine including clinical use and dosing, off label uses and patient ed.) Alpha, Antagonists-pharmacodynamics and pharmacotherapeutics (what does it do and what do you use this drug for?)-Example- antihypertensive, BPH, postural hypotension Beta-adrenergic Antagonists (Blockers)- pharmacodynamics and pharmacotherapeutics All sections especially clinical use and dosing and withdrawal of beta blockers and patient education. Interaction with clonidine and beta blockers. Combined Alpha and Beta Adrenergic Antagonists -pharmacodynamics and pharmacotherapeutics Muscarinic Agonists-pharmacodynamics (what...
Compare and Contrast Diffusion and Osmosis Diffusion Osmosis Is a gradient needed? Direction of movement in relation to the solute) Is a membrane required? Source of energy for movement What is moved
how does aging and smoking influence pharmacokinetics and pharmacodynamics?
Define pharmacodynamics and its relationship to the action of drugs on the body. Discuss dose-response relationships (e.g., basic features of the dose-response relationships, maximal efficacy, and relative potency), the effects drugs can produce, and the amount of drug needed to elicit an effect. Discuss properties of drug-receptor interactions (e.g., drug receptors, four primary receptor families, receptors and selectivity for drug action, theories of drug-receptor interaction, agonists, antagonists, partial agonists, and regulation of receptor sensitivity). Describe how receptors function in the...
Questions I a) What is osmosis? b) What is dialysis? Can MgSO4 pass through? Explain. 2. Can starch pass through a dialyzing membrane? (Support your claim with evidence from the experiment.) 3. Explain why people who are adrift in a lifeboat without a supply of fresh water are advised not to drink ocean water. note - Ocean water is saltier than body fluids like blood plasma. 4. In terms of osmosis, what happens when fresh water is inhaled into a...