Elodea Cells and Solutions with Different Osmolarity Experiment
Introduction
Water is one of the most abundant and yet most important substance here on our planet, in our body cells, even to the smallest organism. Our body consists of up to 60% water, whereas some other organisms can contain up to 90% water (Perlman). All living organisms must keep water level balanced to maintain homeostasis, and to survive. This is where osmolarity comes into play. Osmolarity refers to the concentration of solutes in a solution, closely relating to the movement of water across a membrane (Campbell, 2009).
Before the experiment, the response of Elodea cells in different environments was observed in the lab. Based on observation, my hypothesis on responses of Elodea cells to the different environments are: 1.) Elodea cells would shrink in hypertonic solution with higher concentrations of solute, due to water osmosis down its concentration gradient, diffusing from inside to outside of the cell; 2.) Elodea cells would swell in hypotonic solution with lower concentration of solute, due to water osmosis, diffusing from outside to inside of the cell; 3.) Elodea cells would have no change in solution that is isotonic to the cell, water will diffuse in and out of cell equally.
This experiment will use Elodea plant cells as the research object. Three different tests will be performed to examine how Elodea plant cell would respond in solutions with different osmolarity, and to find out which
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.
The osmolarity of a solution is the concentration measured of a solute. To determine the concentration of a solution, one must first understand what osmosis is and how it works. Osmosis is the spontaneous passage or diffusion of water or other solvents through a semipermeable membrane according to the Britannica Encyclopedia. The semipermeable membrane is one that blocks the passages of dissolved substances such as solutes. This process, in more recent times, provides a more accurate study of how water can diffuse across a cell membrane when water molecules have a high concentration to an area in which they have a low concentration. It was originally studied in 1877 by plant physiologist, Wilhelm, Pfeffer. (Britannica Encyclopedia 2015).
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.
How will the cell change as a result of being placed in different types of liquids? In this experiment we studied and tested the effects corn syrup, vinegar, and distilled water had an egg. When placed in vinegar the egg will double in size because the egg will soak up the vinegar. When placed in corn syrup the egg will shrink in size because the corn syrup will cause the egg to throw everything out.
The lab for this paper was conducted for the topic of osmosis, the movement of water from high to low concentration. Five artificial cells were created, each being filled with different concentrated solutions of sucrose. These artificial cells were placed in hypertonic, hypotonic, or isotonic solutions for a period of 90 min. Over time, the rate of osmosis was measured by calculating the weight of each artificial cell on given intervals (every 10 minutes). The resulting weights were recorded and the data was graphed. We then could draw conclusions on the lab.
Water diffuses across the membrane from the region of lower solute concentration (higher free water concentration) to that of higher solute concentration (lower free water concentration) until the solute concentrations on both sides of the membrane are equal. The diffusion of free water across a selectively permeable membrane, whether artificial or cellular, is called osmosis. The movement of water across cell membranes and the balance of water between the cell and its environment are crucial to organisms. ("Diffusion And Osmosis - Difference And Comparison | Diffen"). A semi-permeable membrane known as the cell membrane surrounds the living cells of both plants and animals. Both solute concentration and membrane permeability are
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
Osmosis is defined as the tendency of water to flow through a semipermeable membrane to the side with a lower solute concentration. Water potential can be explained by solutes in a solution. The more positive a number is more likely it will lose water. Therefore should water potential be negative the cell the less likely it will lose water. In using potatoes the effects of the molarity of sucrose on the turgidity of plant cells. According to Clemson University, the average molarity of a White potato is between .24 M and .31 M when submerged in a sorbitol solution. This experiment was conducted with the purpose of explaining the relationship found between the mass in plants when put into varying concentrations of sucrose solutions. Should the potatoes be placed in a solution that contains 0.2M or .4M of sucrose solution it will be hypotonic and gain mass or if placed in .6M< it will be hypertonic and lose mass instead. Controlled Variables in this lab were: Composition of plastic cups, Brand of Russet Potatoes, Brand of Sweet Potatoes and the Temperature of the room. For independent variable that caused the results recorded it was the different Sucrose concentrations (0.0M, 0.2M, 0.4M, 0.6M, 0.8M, 1M). The dependent variable was the percentage change from the initial weighs to the final. The cup with .4 molarity was the closest to an isotonic solution and was used as the control group for the lab. Water potential is the free energy per mole of water. It is
The aim of the sixteenth of November experiments was to observe how three different solutions with various sucrose concentration influenced osmosis in relation to three onion cells and the impact on the cells structure.
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.
In animal cells, the movement of water into and out of the cell is influenced by the relative concentration of solute
The purpose of this lab is to test the effect of osmosis on cucumber slices. If a cucumber slice is placed in a hypertonic solution, then the mass of the cucumber slice will decrease. Whereas, if