| Investigating Osmosis Through Living Membranes | Introduction: Diffusion is the tendency of molecules or ions to move from an area where they are in higher concentration to an area where they are in lower concentration, that is, down or along their concentration gradient (Marieb 2013). Osmosis is a special case of diffusion defined as the diffusion of a solvent, such as water, through a selectively permeable membrane (Marieb 2013). Osmosis occurs whenever the water concentration differs on the two sides of a membrane. Take a U-shaped container filled with a solution and separate the container into left and right compartments by a permeable membrane. Normally, net diffusion of both solute and water occurs until the concentration of water (and solute) is the same on both sides of the membrane (equilibrium).
Laura Mccain Lab 5: Osmosis with Hypertonic, Isotonic and Hypotonic tonicity Purpose: The purpose of this lab is to familiarize you with osmosis and, specifically, what happens to cells when they are exposed to solutions of differing tonicities. Hypothesis: Hypotonic Solution: the cell has a higher concentration in it than in the area surrounding it. Water moves into the cell to equal out concentration. Isotonic Solution: The cell has a equal proportion of concentration with the area surrounding. Water continually flows in and out to keep concentration even.
Solutes meaning: the substance that is being dissolved, while solvents meaning: substance being dissolved into, much like diffusion. Diffusion can be defined as particles that move from a higher concentration to areas of lower concentration. Diffusion is one of the key processes involved in the movement of materials into and out of cells throughout living systems. Osmosis is the diffusion of the water through a selectively permeable membrane from an area where it is more concentrated to an area where it is less concentrated. Different solutions can be categorized as hypotonic, hypertonic and isotonic as different concentrations.
The solutes are called electrolytes, which maintain healthy bodily functions. When an electrolyte dissolves it breaks up into ions. There are millions of electrolytes within a cell. Water moves inside and outside the cell, with osmotic pressure, which is the force that pulls fluid from one place to another. The level of osmotic pressure is equal in the intracellular fluid, and the extracellular fluid.’ (Study.com, 2015) ‘Osmotic pressure is vital within the human body because it allows water to enter a cell if there is lack of water, and vice versa, if there is too much water within one cell, the osmotic pressure will allows the electrolytes to exit a cell.’ (Study.com, 2015) ‘Intracellular fluid has important functions, it transports food within the cells, it also brings waste products from the cells so that they can be picked up and excreted from the body, and it maintains the shape and size of the cell.’ (Nursing411.org, 2015) ‘Extracellular fluid is located outside the body cells.
A) is neutralized by water B) is surrounded by water molecules C) reacts and forms a covalent bond to water D) aggregates with other molecules or ions to form a micelle in water Answer: B Page Ref: Section 3 11 9) Which would you expect to be most soluble in water? A) I B) II C) III D) IV Answer: A Page Ref: Section 3 10) Solutes diffuse more slowly in cytoplasm than in water because of A) the higher viscosity of water. B) the higher heat of vaporization of water. C) the presence of many crowded molecules in the cytoplasm. D) the absence of charged molecules inside cells.
Louis P Gangarosa et al said iontophoresis of lidocaine drug can provide deeply analgesic effects with shorter time span. The study was showing result of lidocaine hydrochloride decreasing pain. Pain was decreased due to lidocaine drug penetrate more deeply Penetration of lidocaine ion through stratum corneum . Stratum corneum is most resistance layer of the skin iontophoresis lidocaine transfer through this layer Kalbitz et al 1996. Lidocaine ion transfer all layers of tissue through active electrode including ligaments and tendon Massimiliano Nino et al 2010.
D1; Analyse the role of the phospholipid bilayer in terms of the movement of materials into and out of cells The phospholipid bilayer is the structure which surrounds a cell, this plasma membrane is made up of two layers of phospholipids; these are the intracellular layer, which is at the bottom, and the extracellular layer which is at the top (Wisegeek.com/bilayer. 2011). The mosaic model shows that the phospholipids are arranged in shapes like heads and tails, the polar heads are made up of glycerol, phosphate and nitrogen and the non-polar tails are made up of fatty acid chains (Wisegeek.com/bilayer. 2011). The polar heads will interact with water as they are hydrophilic, though the tails/fatty acids are never exposed to water therefore they are hydrophobic (Wisegeek.com/bilayer.
The experimenter used 3 identical plastic cups and filled one with room temperature tap water, one with warm tap water and one with boiling tap water. Each cup was placed into the freezer and was checked every 15 minutes for signs of freezing. The experimenter found that the room temperature water showed the first signs of freezing and in the final outcome froze solid before the water in the other cups. His findings showed that water containing impurities, such as tap water, will freeze faster based on a lower starting temperature. The second case study was covered in an article by Science News.
EXP 2.13: MEASUREMENT OF THE CRITICAL MICELLE CONCENTRATIONOF A SURFACTANT ABSTRACT The aim of this experiment is to measure the critical micelle concentration of sodium dodecysulphate. This will be done by using the conductivity method which will involve measuring the conductivity of a solution during a titration. The second part of the experiment will involve using spectrophotometric method to determine the maximum wavelengths at different concentrations. INTRODUCTION in colloidal and surface chemistry the critical micelle concentration (CMC) of a surfactant is the concentration where micelles begin to form [1]. Surfactants are compounds that contain hydrophobic and hydrophilic groups.
Solubility and Conductivity Introduction Solubility by definition means “the quality or property of being soluble; relative capability of being dissolved” and in chemistry this tells us whether or not a substance is dissolvable, but in the medical field it can mean you have a homeostatic imbalance (Webster, 2010). They use “a screening test for sickle cell hemoglobin (Hb S), which is reduced by dithionite and is insoluble in concentrated inorganic buffer; addition of blood showing Hb S to buffer and dithionite causes opacity of the solution” (Solubility, 2012). This is just one of many uses of solubility in the medical field. Conductivity by dictionary definition is “Physics. The property or power of conducting heat, electricity, or sound” and is used as such in chemistry (Dictionary, 2014).