Osmosis Lab

Introduction Water is known as the universal solvent. A solvent has the ability to dissolve another substance, which is known as the solute. The solute and solvent together are known as a solution.

Introduction: Osmosis is diffusion of water from areas of high water potential to areas of low water potential. It does not require an input of energy. Plants use osmosis to transport minerals from their roots to their leaves, and to take in water in the soil. Because the plant cell is taking in water and minerals, its mass increases. The Maryland Department of Natural Resources states that “plants use water to carry moisture and nutrients from the roots to he leaves and food from the leaves back down to the

This is an individual study investigating the process of diffusion, osmosis and active transport. To start you should know that substances are moving in and out of cells of your body all the time. To understand and make sense of the cells of your body, you need to know about

Introduction Osmosis is the passive movement of water from an area of low solute concentration to an area of high solute concentration, normally across a membrane which prevents the movement of solvent. This is a process by which materials may move into, out of, or within cells. Osmosis doesn’t depend on energy provided by living organisms but is affected by the properties of the cell membrane. The rate of osmosis is dependent on such factors as temperature, pressure, molecular properties such as size and mass, and the concentration gradient. In osmosis, the relationship between a solute’s concentration outside of cell and inside of a cell is described in terms of the tonicity of the solution outside of the cell. A cell is in a hypotonic solution when the solute is more concentrated inside the cell and therefore water moves into the cell. In this solution the cell swells as water enters, this may continue until it ruptures or hemolyzes. In the reverse condition, the cell is in a hypertonic solution

Background Information: Diffusion is defined as the movement of molecules from an area of high concentration to an area of low concentration. The diffusion of water molecules through a semi-permeable(selectively permeable) membrane is osmosis. Semi-permeable means that some molecules can move through the membrane while others can not. Diffusion and Osmosis are passive forms of transport requiring no energy. Active Transport utilizes energy in the form of ATP. Water is a solvent that can dissolve a number of substances more than any other substance. Wherever water goes, through the ground or a body, it takes along valuable molecules. Water’s chemical composition causes it to be attracted to many different molecules and be attracted so strongly it disrupts the forces and dissolves it. Water can pass through the semipermeable membrane without any help but can change the solution, on the other side of the cell membrane, depending on how much it diffuses in and out.

This situation is called dynamic equilibrium. 5. Experiment: Click Reset. Check that the Solute outside is 10 and the Initial cell volume is 40%. To calculate the solvent concentration, divide the number of solvent particles by the total number of particles, and then multiply by 100. (Note: The Gizmo only displays the solute concentrations.)

EDVOTEK, Inc. • 1-800-EDVOTEK • www.edvotek.com EVT 080423AM 2 AP Biology EDVO-Kit # 281 Principles & Practice of Diffusion and Osmosis Table of Contents Lab # 1 A system is Material moving most stable when it has reached equilibrium. A out of the cell system will tend to go to equilibrium (lowest, accessible energy state) in the absence of added energy (Figure 2).

Introduction All cells contain membranes that are selectively permeable, allowing certain things to pass into and leave out of the cell. The process in which molecules of a substance move from an area of high concentration to areas of low concentration is called Diffusion. Whereas Osmosis is the process in which water crosses membranes from regions of high water concentration to areas with low water concentration. While molecules in diffusion move down a concentration gradient, molecules during osmosis both move down a concentration gradient as well as across it. Both diffusion, and osmosis are types of passive transport, which do not require help.

ESSAY ‘The structure and importance of the plasma membrane found within and around all cells’ The plasma membrane surrounds all eukaryotic and prokaryotic cells. Eukaryotic cells have membrane bounded organelles whereas prokaryotic cells do not. The plasma membrane forms the boundary between the cell cytoplasm and the environment. Its function are to

A semi permeable membrane. (Biology at Aveson , 2007) Figure 2. A semi permeable membrane. (Biology at Aveson , 2007) pass through the membrane and into the cell. Despite its importance osmosis may also damage cells by causing them to; a) shrink from water loss or b) burst from too much water gain. Plant cells [fig 3] have adapted themselves to ensure that these factors do not affect them, by forming a ridged wall, known as the cell wall, around their cells. The cell wall maintains the shape of the cell, and prevents the cell from bursting in a hypotonic medium by resisting water pressure. Plant cells have also adapted a larger vacuole, which occupies 80% or more of the cells cytoplasm (Davidson, 2004); allowing plants to store more water and nutrients per cell. Vacuoles also play a structural role in plant cells; by swelling when liquids contact them, plant vacuoles are able to control turgor pressure within the cell. This helps maintain the structural integrity of the cell as well as providing the plant with suitable amounts of water and nutrients; however the cell will never burst because the vacuole is contained within the cell wall. If plant cells are deprived of water their vacuole will begin to shrink, yet due to the cell the wall, the plant cell will be able to maintain its shape. [fig.4] Animal cells [fig 5] on the other hand do not have this

Abstract: Diffusion occurs as passive transport in cells through a selectively permeable membrane. In this experiment, the membrane that was used was dialysis tubing. The questions this experiment modeled were, which solutions would diffuse and what molecules were small enough to diffuse through the selected membranes. When the experiment concluded, the data supported which solutions diffused and at what rate they diffused. It is discussed that the permeability of a solute across a membrane is affected differently from method to method. Each process has comparable variables that will affect the rate or ability to diffuse, but some require more work, energy, or other substances needed to allow diffusion to occur.

The 3 types of cellular transport that I am including are Osmosis, Active Transport, and Facilitated Diffusion. Osmosis allows water to move from a region of lower solute concentration to a region of higher solute concentration until both sides are equal. During Osmosis, only water molecules can pass through, and sugar molecules cannot pass through the membrane. This process requires no energy from the cell. An example of osmosis is in an hypotonic red blood cell, which will cause the cell to burst due to the cell having too much water. Cells can regulate water concentrations through osmoregulation. Active transport requires energy because it pumps solute against its concentration gradient. Energy for this work is usually supplied by ATP. To

INTRODUCTION Osmosis is the movement of water molecules from high concentration to low concentration through semipermeable membranes, caused by the difference in concentrations on the two sides of a membrane (Rbowen, L.). It occurs in both animals and plants cells. In human bodies, the process of osmosis is primarily found in the kidneys, in the glomerulus. In plants, osmosis is carried out everywhere within the cells of the plant (World Book, 1997). This can be shown by an experiment with potato and glucose/salt solution. The experiment requires putting a piece (or more) of potatoes into glucose or salt solution to see the result of osmosis (a hypertonic type of solution is mostly used as it would give the most prominent visual prove of

Introduction Diffusion is one of two passive process membrane transports that moves molecules from a region of their higher concentration to a region of their lower concentration and has a driving force of kinetic energy. Simple diffusion, which is what this experiment is about, occurs without the assistance of membrane proteins

The Transport of Substances Across the Plasma Membrane The plasma membrane or, the cell surface membrane, is made almost entirely of protein and lipid. The plasma membrane controls the movement of substances into and out of a cell. It is partially permeable