Osmosis is the transfer of water molecules from places where there is a lot of water molecules to places there are not many water molecules. When the cell is selectively permeable it allows certain substances in and out of the cell. There are three terms for the amount of solute in a cell isotonic, hypotonic, and hypertonic. Isotonic means there is a balance of solute inside and outside of the cell. Hypotonic is when there is lower concentration of solute in the cell than the concentration outside of the cell. Hypertonic means there is a more solute in the cell than outside of the cell. The molecules want to reach equilibrium, or balance out the amount of water inside and outside the cell. In this alcohol investigation, the purpose was to …show more content…
This is true because in Osmosis the water wants to go to the place where there is a small amount of water to balance out the concentrations. The cup, when it was filled with 30% and 70% alcohol, had the water inside the cell leave to go balance out the lowered concentration of water. Notice in the graph below, when there was 0% alcohol in the cup the weight increased. Unlike the trials for 30% and 70% alcohol the cell gained weight because it did not have to go dilute another substance, so the water did not have to leave the cell to maintain equilibrium. All of this means that when there is another substance, the concentration of water changes causing osmosis to occur balancing out the concentrations. This evidence supports the claim because once the alcohol entered the cup it changed the concentration of water on the outside, making the water leave the cell to balance out both concentrations. Again, osmosis is when the water from a high concentration goes to a low water concentration. During the trials with 30% the substance mixture outside of the cell was hypotonic, meaning that the concentration of solutes, or a substance that dissolves in another, was lower than the concentration of solvents, the substance that dissolves. In the trial with 70% alcohol in the cup, the situation is flipped and the outside of the cell is hypertonic, meaning there is a high concentration of solute and a low concentration of solvent. In this case the solute is the alcohol and the water is the solvent. Looking at others arguments, other groups support the claim stated at the very start of this argument. Other groups all had something along the lines of “when there is an increasing amount of alcohol the amount of water in the cell
Osmosis • Introduction This experiment will prove how osmosis occurs by using dialysis bags, the water molecules will move through a semipermeable bag from a higher concentration to a lower concentration of water. Each beaker will represent hypertonic, hypotonic, and isotonic solutions. This experiment will demonstrate the process of osmosis in different solutions. Definitions of the main concepts used in this experiment: - Osmosis is the net movement of water molecules across a semipermeable membrane from an area of lower solute concentration to an area of higher solute concentration.
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 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.
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 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).
Cells are always in motion, energy of motion known as kinetic energy. This kinetic energy causes the membranes in motion to bump into each other, causing the membranes to move in another direction – a direction from a higher concentration of the solution to a lower one. Membranes moving around leads to diffusion and osmosis. Diffusion is the random movement of molecules from an area of higher concentration to an area of lower concentration, until they are equally distributed (Mader & Windelspecht, 2012, p. 50). Cells have a plasma membrane that separates the internal cell from the exterior environment. The plasma membrane is selectively permeable which allows certain solvents to pass through
The major objective of the experiment was to test the effect of the concentration gradient on the diffusion rate. It was hypothesized that the greater the stronger the concentration gradient, the faster the rate of diffusion would be. To test this, dialysis tubes were submerged in different concentration fructose solutions. We weighed the tubes at specific time intervals to measure the rate of diffusion of water in each different solution. The results illustrated that increased concentration gradient increases the rate of diffusion of water in the tubes. We concluded that as concentration of the
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.
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
We know that osmosis is the movement of water by diffusion through a selectively permeable membrane and the molecules will move around to reach an equal balance (equilibrium). We believe that osmosis will occur because the water molecules are small enough to get through the membrane. The independent variable
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 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.
I hypothesized that if the concentration would increase, then the osmosis would too in the same way. Such as the concentration goes from 20% to 40%, the rate of osmosis doubles as well. Even after finding out the human error from the lab prep crew, who switched the 30 percent with the 40 percent concentration, making our data for 30 percent truley for 40 percent and vice versa. If you look at figure xx, you can see that the osmosis rate for 20 percent and 30 percent, which we now know is truley 40 percent, almost triples. From when the concentration goes from 20 percent with a osmis rate of .039g/ml to 40 percent with a osmic rate of .095g/ml.
Throughout this experiment I learned the basis for Osmosis. Our experiment and data helped me further understand the variation of osmosis and water potential. In our first experiment we learned that the overall mass will increase due to the starch and glucose in the dialysis bag. This is what I predicted to happen since the concentration of water is lower in the bag than in the distilled water. The water always moves down its concentration gradient by osmosis.
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.