How Does Diffusion And Osmosis Affect The Rate Of Diffusion

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.

Research Question: How does the size of the cell affect its efficiency in exchanging substances through several ways, like diffusion?

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.

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 reasoning behind this experiment is the examine whether the rate of osmosis is changed due to a change in temperature. It was hypothesized that the rate of osmosis will increase as the temperature of the sucrose is increased. The rate of osmosis was tested by using the different jars full of different temperate water and testing how high the water rose on an osmometer over a span of 20 minutes. An osmometer is a tool used to measure rates of osmosis. The different temperatures tested on a sucrose solution were 5 degrees Celsius, 20 degrees Celsius, and 37 degrees Celsius. Rates of osmosis were higher in the hot water than in the cold water and control. The results showed that the rate of osmosis increased as the temperature increased, henceforth the hypothesis was supported. In conclusion, the experiment showed how changes in temperature affect the rate of osmosis.

Diffusion is the movement of molecules from a region of higher concentration to a region of lower concentration. The rate at which molecules diffuse can be determined by the relationship of molecular weight and that rate of diffusion through a membrane. Hypothesis of this experiment is that the fluid with higher molecular weight will diffuse at a slower rate and distance.

The claim to this Agar Pieces lab is that the cells that have a larger surface area to volume ratio are more efficient at diffusing essential nutrients. Another solution, is the rate of diffusion is related to cell size. Nutrients diffuse at a faster rate through small cells than they do through large cells. In this lab of Agar gel, the purpose of this experiment is to find the surface area and volume of the cell that may affect the ability of the molecule to be able to diffuse the cellular space.

Diffusion is the transfer of molecules from an area that has a higher concentration to an area that has a lower concentration. Osmosis is the diffusion of water. The purpose of this experiment was to study the process of osmosis. In order to test osmosis, eggs that had been soaking in vinegar were taken and placed in four beakers of solution with different levels of glucose. Using this experiment we were able to determine the rate of osmosis of different solutions, with various amounts of glucose, through eggs. In the results of this lab it was found that the eggs were either hypertonic or hypotonic and that the

The diffusion across a cell membrane is a process of passive and spontaneous net movement of small lipophilic molecules. The molecules move from a high concentration to a low concentrated region along the concentration gradient. The result being a point of equilibrium, this is where a random molecular motion continues but there is no longer any net movement. However, there are things that can affect the rate of diffusion, these being temperature, surface area, concentration, size of the molecule, permeability, diffusion distance and concentration difference. Osmosis is a type of diffusion as it is the movement of water molecules through a semipermeable membrane into a region of higher solute concentration. Equilibrium is reached when the solute concentration is equal on both sides. Water potential is measured in kiloPascals, it is the measuring of the concentration of free water molecules that are able to diffuse compared to pure water, which is 0 kilopascals. It is a measure of the tendency of free water molecules to diffuse from one place to another. The result being, the more free water molecules, the higher the Water Potential. However, Water potential is affected by two factors: pressure and the amount of solute.

In our lab, we were hoping to determine how cell size impacted the rate of diffusion. The results of the lab, showed that the smallest cube (1cm) diffused the most because the area of diffusion took up a majority of the surface area. This relates to cell size and rate of diffusion, because the agar cubes were supposed to be the cell and the amount of pink that diffused into the cube was supposed to show the rate of diffusion, and how smaller cells were able to diffuse faster and more easily than larger cells. This explains why smaller cells are more efficient in our bodies.

Diffusion and osmosis are examples of passive transport, which was shown in the lab. Due to diffusion and osmosis, solutions can either be hypotonic, hypertonic, or isotonic. Solutions that are hypotonic have more solute concentration inside the cell than outside the cell. Solutions that are hypertonic have less solute concentration inside the cell than outside the cell. A solution that is isotonic has an equal amount of solute concentration inside and outside the cell. Now, the goal of this lab was to see if red blood cells appear bigger after being exposed to distilled water. (If the cell appears bigger, than it shows that the solution is hypotonic. If the cell appears smaller, than it shows that the solution is hypertonic.

Both parts of this case study exemplify osmosis, which is a form a diffusion. Diffusion is when the particles of a given substance, inside and outside of any cell, move back and forth across the cell membrane. The majority of cells move from high concentration to lower concentration (Nave). Osmosis is unique because it specifically describes the diffusion of free water molecules.

The purpose of this lab was to demonstrate osmosis and diffusion using model cells. As mentioned, osmosis is when water molecules passively move across a semi-permeable membrane (Russell et al., 2013). In the model cells, the dialysis tubing represents the semi-permeable membrane. Model cell one demonstrates that osmosis occurred because osmosis caused the water to move through the dialysis tubing and into the cell. On the other hand, model cell three showed that a cell would lose water via osmosis in a situation where the solution concentration is higher than the solution in the cell. Model cell one and model cell three both demonstrate that molecules move from high to low concentration. Consequently, this shows that my hypothesis, that osmosis and diffusion will occur between the solutions of different concentration, but not between the solutions of the same concentration, was correct. It is important to note possible errors that may have occurred during this experiment that may have skewed the results. For example, if the string was not tied tight enough around the ends of the model cells the solution inside the cells could have leaked out. This would have skewed the results of the experiment. Model cell two appeared to

This is how cells maintains homeostasis. Diffusion is a process that molecules perform to move from higher concentrations to lower concentrations. The molecules move to lower concentrations to create an equilibrium, a state of balance. Some molecules cannot move through the plasma membrane because the membrane is selectively permeable. This means that only certain substances are allowed to pass through. Osmosis, the diffusion of water molecules from high to low concentrations, was performed in the investigation. The solutions of alcohol were hypertonic, containing higher concentrations of solutes, to the cells, which were hypotonic, containing a low concentration of solutes. The solution of 0% alcohol was isotonic to the cell. Meaning that there is the same amount of solutes inside and out of the cell. The alcohol is impermeable to the membrane in this investigation because the molecule is bigger. Water, on the other hand, is permeable to the membrane. Since the solutions have higher concentrations of the solute(alcohol) than the cell, they get dehydrated and need more water. Therefore, the cells have 100% water so the water exits the cell into the substance so it can be in the lower concentration; creating the

Diffusion can be defined as the movement of certain molecules down to their concentration gradient (from the side with higher concentration of solute, to the side with lower concentration of solute) through a selectively permeable membrane. However, the movement of substances through the cell’s cytoplasm must be analysed as well since, after they have crossed the membrane, they will have to reach the organelles. The dimensions of a cell are deeply influenced by the rate of this process, because bigger cells will have a less immediate and efficient access to those substances. When the molecules are small enough to get through the pores between the phospholipids, a simple diffusion can happen. On the other hand, when the aid of channel or carrier proteins is necessary, we are talking about facilitated diffusion (5). Facilitated diffusion can happen both because the molecules are too big and because they are lipid-insoluble or ions. In these cases, the substances are not allowed to cross the phospholipids bilayer and need the help of some proteins present in cell membrane (6).