Osmosis Lab

The experiment of the lab was to demonstrate knowledge of the concepts of diffusion and osmosis. Diffusion is the movement of substances moving from a high concentration to a low concentration. For this lab the rate of osmosis was measured in concentration. The concentration stayed the same and increased through the experiment. At the beginning of the experiment the sacs were weighed to determine the tonicity of water throughout the experiment. Timing was also a factor each 15, 30, 45 minute interval the sacs were weighed and recorded. Each sac had a different amount of solution in them. The tonicity of the sacs was determined as well by the final weights and the final percent of gain or loss of water in the sacs.

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.

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.)

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 the process of diffusion, osmosis and active transport.

1. The relationship between rate of diffusion/ osmosis, volume, and surface area can be easily seen and analyzed through the data that was collected from procedure one: Surface Area and Cell Size. Phenolphthalein is a dye-material in this lab that was used to determine whether a substance was an acid or base. This could be told as the phenolphthalein changed into a murky. Muddled and clouded color when mixed with acids. When the chemical aid was mixed in with a base, the color

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 so some substances cross more easily than others.

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

Diffusion, osmosis and active transport of substances in and out of the membrane is very important for all types of cells. One example is the root hair cell. These cells are the exchange surface in plants which are responsible for the absorption of water and mineral ions so without osmosis and active transport this would not be possible. The water is taken up by osmosis through the partially permeable membrane. The root hair cells are surrounded by a soil solution which contains small quantities of mineral ions but mainly water, so has a high water potential (slightly less than zero). The root hair cells themselves contain a high quantity of amino acids, mineral ions and sugars inside them (low water potential). Therefore water will move by osmosis from the soil solution and into the root hair cells, going down the water potential gradient.

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

Hannah Niehaus Bio Lab 111 W 1-4:50 Valerie Sponyoe Increased Sugar Concentration Increases Rate of Osmosis Introduction: Osmosis is a critical process of life in which water diffuses across a semipermeable membrane from an area of lower concentration to an area of higher concentration. Osmosis is a type of passive transport, in which no additional energy is needed for a solution to reach equilibrium. In order for osmosis to occur there must be a selectively permeable membrane that allows the transfer of water molecules and a concentration gradient of a specific solute that is unable to diffuse across said selectively permeable membrane (Eisenbach et al. 2018). A hypotonic solution in relation to the cell will cause the cell to swell while

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.

Measuring Osmosis: Potato Cores Introduction: The purpose of this experiment was to understand what osmosis is and to be able to measure it. Osmosis is the movement of water and the water moves from area with high concentration to an area with low concentration. During that lab potatoes were cut up to a of total of four pieces of potato per cup, with a total of six cups and twenty-four pieces of potato.

The goal of this lab was to try and understand the effects of osmosis on living cells and to be able to calculate water potential of living cells. This hypothesis was tested because it’s important to know how much water a cell can obtain without bursting. The process that this lab was based on is osmosis, which is a type of diffusion. “Diffusion is the movement of molecules from a high concentration to a low concentration”(Anderson). Osmosis is the process of diffusion but involving water moving from a higher concentration to a lower concentration. Osmosis affects cells because if a cell has a low concentration of water, whenever water is absorbed into an organism the water will naturally move into the cells with the least amount of water because

(Marieb 2013) Osmosis, is a special kind of diffusion, is defined as the diffusion of water through a semi-permeable membrane from a higher concentration to that of a lower concentration. The concentration of water is inversely related to the concentration of solutes. If the water can diffuse across the membrane, both water and solutes will move down their concentration gradients through the membrane. (Marieb 2012) There are three terms used to describe the concentrations of solute particles of different solutions: Hypotonic- When compared to another solution of different concentration, the solution contains the lower concentration of solute particles. Water moves across a semi-permeable membrane out of a hypotonic solution. Hypertonic- When compared to another solution of different concentration, the solution that contains the higher concentration of solute particles. Water moves across a semi-permeable membrane into a hypertonic solution. Isotonic-Having the same concentration of solute particles as another solution. There is no net flow of water across the membrane. In animal cells, the movement of water is affected by the relative solute concentration of the plasma membrane. As water moves out of the cell, the cell shrink and if water moves into the cell, the cell swells and may even burst.

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