Osmosis Lab

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

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 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.

If Michael’s mistake had been caught earlier, is there anything that could have been done to prevent the corn from dying?

The difference is that along with large molecules, living cells prevent molecules with positive charges and solubility. This is not representing in dialysis tubing, and is only found in living cells because the tubing is only based on molecular size (98). When referring the rate of diffusion, the concentration gradient influences the diffusion rate, based on the factors of temperature. The ability for molecules diffuse from high to low concentrations primarily depends on the concentration gradient between the two areas.(96-99). My hypothesis for the study is that in the hypotonic, hypertonic, and isotonic solutions, the direction and rate of osmosis will determine based on the concentration inside the dialysis tubing. My prediction is that if the solution is hypotonic the results will decrease, if the solution is hypertonic the results will increase and if the solution is isotonic the solution will vary and or remain constant.

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

The objective of this experiment is to develop an understanding of the molecular basis of diffusion and osmosis and its physiological importance. Students will analyze how solute size and concentration affect diffusion across semi-permeable membranes and how these processes affect water potential. Students will also calculate water potential of plant cells.

The following hypothesis was made in regard to effect of the concentration gradient on the rate of diffusion: The higher the concentration gradient, the faster the rate of diffusion.

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

Osmosis is a special type of diffusion where water molecules move down a concentration gradient across a cell membrane. The solute (dissolved substance) concentration affects the rate of osmosis causing it either to speed the process up or slow it down. Based on this, how does different concentrations of sucrose affect the rate of osmosis? If sucrose concentration increases in the selectivity-permeable baggies, then the rate of osmosis will increase.

Introduction Osmosis is crucial to the natural world and is need order to maintain life in every individual cell. Without it cells wouldn't be able to transport necessary materials in and out of the cell. For example, if a human being is severely dehydrated, then first thought would be to pump pure water into their system in order to hydrate. Water would enter the cell when its normal state, meaning the cell has a lot less water inside it than out.

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

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).

Osmosis is when water passes through a cell membrane, it is also form of a diffusion, which is a form of passive transport. Osmosis will continue to until an equilibrium is reached which is when the solutions are isotonic. This means that the solution has the same amount of solute on both sides. If the solution is hypertonic, it has more solute in the solution. In this situation water will move towards it. if the solution is hypotonic, it has less solute in the solution. Whereas in this situation, water will move out of the solution.