Diffusion Essays

Review Sheet Results

1. Explain why increasing extracellular K+ reduces the net diffusion of K+ out of the neuron through the K+ leak channels. Your answer: Because outside a typical cell, the concentration of K+ is about 5mM and the concentration of Na+ is about 150 mM. When you increase the concentration of K+ from 5 to 25 mM and reduce concentration of Na+ from 150 to 130 mM, the outside has more concentration of K+. The membrane is permeable to a particular…

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Egg Lab Report

An egg is a model of a human because the egg has a cell membrane like humans do inside and outside of the body that let things pass through like water. We can use eggs to study the effect of changes in the external environment on the internal environment by having harsh environments like putting the egg in only alcohol and see what happens to the inside of the egg. Diffusion is the movement of a substance down its concentration…

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A Selectively Membrane Means That the Cell Membrane Can Only Control Over Certain Things

Osmosis is the diffusion of water through a selectively permeable membrane. A selectively membrane means that the cell membrane can only control over certain things that come in and out through the membrane. A membrane is just the structure surrounding the cell. Throughout osmosis, the cell could either get larger, or smaller. If the cell gets larger it means that it was put into a hypotonic solution, and result to the cell exploding. If the cell gets smaller, it means…

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The Rate of Diffusion

Abstract I found that this experiment gives me an understanding on how osmosis and diffusion works. In its simplicity, it explains the process that our bodies (mainly cells) use all the time. It also showed me that even with the temperature changing, it doesn’t drastically change the rate of diffusion. Introduction Diffusion is important in all living systems. Osmosis is the passage of water from a region of high water concentration through a semi-permeable membrane to a region of low water concentration (Purchon…

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Cell Transport Mechanisms

Describe two Variables that affect the rate of diffusion. The two variables that affect the rate of diffusion are: A. The size of the molecule. The larger molecule will diffuse more slowly than the smaller molecule. B. The nature of plasma membrane. If the membrane is composed of lipid portion., only lipid soluble molecules can pass through while water molecules cannot. 3. Why do you think the urea was not able to diffuse through 20 MWCO? How well did the…

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Physio Ex 9.0 Activity 1 Cell Transport Mechanisms and Permeability

ACTIVITY ONE- Cell Transport Mechanisms and Permeability: Simulating Dialysis (Simple Diffusion) 1. Describe two variables that affect the rate of diffusion. Molecular weight affects the rate of diffusion because the bigger the size of the molecule the longer it will take to diffuse. Membrane size is another variable that affects the rate of diffusion because if the membrane’s pores are small it will take molecules longer to diffuse though it than if the pores were larger. Also, membrane thickness is…

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Cell Transport Mechanisms and Permeability

1.Describe two variables that affect the rate of diffusion. a.Molecular weight  b.Solute concentration  2.Why do you think the urea was not able to diffuse through the 20 MWCO membrane? How well did the results compare with your prediction? a.Urea was unable to diffuse through the 20MWCO membrane because urea is a big molecule and the 20MWCO membrane pore size was too small for Urea. My predication was accurate, as I predicted that Urea would not be able to diffuse through…

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Gas Diffusion

OBJECTIVES: Determine the gas diffusion coefficient of acetone using the established Winkelmann’s method KEYWORDS Diffusivity, Gas Diffusion Coefficient, Winkelmann’s method OVERVIEW The knowledge of physical and chemical properties of certain materials is important because very often process engineering deal with the transformation and distribution of these materials in bulk. One such property is diffusivity. Mass transfer by diffusion takes place when there is a concentration gradient of the diffusing component. Naturally, the diffusion in gas phase is much faster than…

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Diffusion Across a Selectively Permeable Membrane

Introduction: Diffusion is movement of molecules from one area of concentration to another. This process is vital for the life functions of cells. Cells have selectively permeable membranes that allow only certain solutions to pass through them. Osmosis is a special kind of diffusion that allows water to go through semi-permeable membranes of high water potential to a region of lower water potential. Water potential measures the tendency of water to leave one place and into another. Diffusion and osmosis…

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Bystander Effect

Psychology Interview Questionnaire 1. What is the bystander effect/diffusion of responsibility in your own opinion? 2. What is the Malaysian’s level of awareness towards the bystander effect? 3. How is the ‘bystander effect’ situation in Malaysia at the moment? 4. What are the factors that cause the bystander effect? 5. What triggers someone to help only after they see another person take action first? 6. Does time factor play an important role when such occurrence takes place? Will it happen…

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Simulating Dialysis

Why do you think the urea was not able to diffuse through the 20 MWCO membrane? How well did the results compare with your prediction? __ The molecules were to large to go through. My results matched._ 3.Describe the results of the attempts to diffuse glucose and albumin through the 200 MWCO membrane. How well did the results compare with your prediction? __The albumin was not able to go through and the glucose did. I predicted that neither of them…

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