Osmosis : Observing Elodea Leaves And Plasmolysis

As the lab introduction explains, osmosis is relatively permeable to water and will follow solutes. By instinct, the water will move from a more diluted solution to more of a concentrated solution. The products of the experiments concluded the physiological significance of osmosis by how cell membranes in the body are semipermeable meaning that only certain molecules can pass through it. When intracellular fluid and extracellular fluid are at equilibrium by non-penetrating and concentrated solutes, no net movement of water goes in and out of the cell. Furthermore, if the ECF changes in osmolality, then depending on the difference between the ECF and ICF will determine whether water moves in or out of the cell. This is important in the cell membrane as small differences in osmolarity correspond to large, rapid change in osmotic pressure, causing cells to gain or lose water. In sum, our body makes critical decisions in what molecules are allowed to penetrate the cell membrane and make sure that our red blood cells don’t cause any problems within the

Osmosis is a natural occurrence constantly happening within the cells of all living things. For osmosis to occur, water molecules must move across a semipermeable membrane from an area of low concentration to an are of high concentration. In order to understand osmosis, people must understand the different types of concentrations that can be present within solution. One of them is an Isotonic solution where the concentration of dissolved particles is equal to that of a cell’s. Another is a hypertonic solution where there is a higher concentration of dissolved particles then inside the cell. And lastly there is a hypotonic solution where there are less dissolved particles than inside the cell. As dissolved particles move to a region of lower concentration, water moves the opposite direction as a result of there being less water in the highly concentrated region. In this experiment, gummy bears were placed in salt water, sugar water, and tap water to find the measure of osmosis between the solution and gummy bear.

Osmosis is described in one of three ways when comparing more than one solution. The cell’s external and internal environment helps determine tonicity, which is defined as how the cell reacts to its environment. When the cell’s environment is equal in osmolarity to itself and there is no change, it is considered an isotonic solution. When the environment has a higher osmolarity, shrinkage occurs and it is considered a hypertonic solution. When the environment has a lower osmolarity, swellings occurs and it is considered hypotonic.

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.

The Osmosis and Diffusion lab was conducted to provide us with information on how built up mucus affects those conflicted by the recessive genetic disease, Cystic Fibrosis., due to a mutation to the membrane regulating chloride (Cl-). This mutation prevents the Cl- from leaving the cell causing the amount of sodium (Na+) in epithelial cells, which results in extreme mucus on the lungs and airways causing this disease to be fatal if not treated but treatment does not equate to a long lifetime. During the lab we took the data from three parts: Diffusion, Osmosis in an Elodea Cell, and finally the Role of Osmosis in Cystic Fibrosis. During Part 1 we looked at diffusion across a semipermeable membrane for starch and glucose, which resulted in both having a negative solution when placed in a semipermeable membrane. Then we looked at osmosis in the Elodea Cell to watch for the occurrence of Plasmolysis, when a cell’s plasma membrane pulls away from the cell, and how a plant cell is affected by both hypertonic and hypotonic solutions. Finally, we observed the role of Osmosis in Cystic Fibrosis using dialysis bags to represent a normal cell and a Cystic Fibrosis cell with the normal containing 1% NaCl while the Cystic Fibrosis bag contained 10% NaCl. After we ran the experiment, we looked at the Percent Change in Mass and compared them after 30 minutes. We found that Cystic Fibrosis cells didn’t change mass as much as the normal cell ending with a change in mass over -1%. The

The main purpose of the experiment was to test the idea that water would move from the higher concentration to the lower concentration. In order to test this theory, we placed potato slices in 7 different containers, each containing different concentrations of NaCl, to measure the weight change from osmosis. The containers ranged from 0M NaCl all the way to .6M NaCl. We measured the potato slices before and after placing the slices in the solutions and recorded the net change in weight to determine the tonicity of the potato cells. Our results showed that the potato slices put in a NaCl solution of .2M or higher lost weight and the potato slices put in a NaCl solution of .1M or lower gained weight. This shows that the osmolarity of the potato falls within the range of .1M to .2M, and it also proves the process of Osmosis by having the higher concentration move to the lower concentration. In addition to this, it can be concluded that the osmolarity of cells can be determined by observing the affects of osmosis.

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

Osmosis is a process in which molecules in a solvent pass across a semipermeable membrane into a more concentrated solution from a less concentrated one, attempting to make both sides isotonic or equal to each other. Isotonic can also be described as an equilibrium, where there is no net movement of the molecules. Osmosis is relevant in everyday life whether the general population is aware of it or not. It could be as simple as sitting in the pool too long and getting pruney fingers or as complex as a cholera infection in the intestinal cells that does not allow the intestinal cells

The observation under the microscope of a cell of an onion skin soaked for 15 minutes in a 0.5 molar sucrose solution showed a cell membrane just beneath the cell wall. The cell wall had a rectangular shape. See diagram 3 for sketch. The cell and its surrounding were in an isotonic solution. The two solutions in the cell and out (0.5 molar sucrose solution) of the cell were homogenous. No net movement of water and change in the cell structure was observed. The components of the solute and solvent were evenly intermixed. The concentration of solute and solvent on either side of the cell membrane was equalized. Because the onion tissue didn’t get any water the cell was flaccid and nonturgid.

Osmosis is a special type of diffusion. It is the diffusion of water across a semipermeable membrane which is a membrane that is freely permeable to water but is not freely permeable to solutes, the water moves from a dilute solution to a more concentrated solution (Karp, 2010). Both diffusion and osmosis are passive transport, energy is not used in the transport. In osmosis water moves across a membrane toward the solution of greater concentration, because the concentration of water is lower there (Martini and Bartholomew., 2007).

Plant cells react differently to osmosis than animal cells. When an animal cell is placed in a hypertonic solution, water will leave the cell causing it to shrink, this is known as crenation. When a plant cell is placed in a hypertonic solution the cell membrane will pull away from the cell wall, making the plant flaccid, this is known as plasmolysis. When an animal cell is placed in a hypotonic solution, water will rush in to the cell, causing it to swell and sometimes burst. A plant cell placed in a hypotonic solution will also swell due to water rushing in, but will resist rupturing due to the rigid cell wall. Plant cells become more rigid in a hypotonic solution.

In osmosis, the flow of the water from or to a cell depends on whether the cell is immersed in a solution that is isotonic, hypotonic, or hypertonic to the solution. If the cell is isotonic to a solution, this means that the solute concentration of a cell and its environment is the same and therefore there will be no movement of water. If the solute concentration is lower than that of the cell, then water will flow into the cell, causing it to expand. If the solute concentration is lower than that of the cell then water will flow out of the cell, causing it to shrink.

The hypothesis is that when cells are put in a solution with a different water potential than inside of them, cells will gain or lose water. If concentration of solution is the same, there will be no change in mass.

Because chlorophyll-a takes in violet-blue, and orange-red lights to use in photosynthesis, it reflects green, and that is the color we see. This study investigates the relationship between the wavelength of light and the total respiration of the plant Elodea. The purpose is to see the effect of the presence or absence of certain wavelengths can have on the process of photosynthesis. Because Elodea is a plant that reflects green light, it can be assumed that red lights, the complimentary color to green will be absorbed the most contributing to the process of photosynthesis and respiration making the most oxygen.

This experiment was used to examine the hypothesis that: Osmosis is dependent on the concentrations of the substances involved.