Rationale The cell membrane, also called the plasma membrane is found in all cells and separates the extracellular side of the cell from the cytosolic side (Cell membrane (plasma membrane), 2023). The purpose of the cell membrane is to communicate with the cell’s external environment, to contain the cell’s contents and to control the transport of molecules in and out of the cell. Diffusion is the passive movement of molecules from an area of high to low concentration. The cell membrane is semi-permeable, meaning some substances can pass through but others cannot. Osmosis is the diffusion of solvent molecules (e.g. water) across the membrane from an area of high concentration to an area of low concentration (Lopez & Hall, 2022). When the fluid on the extracellular side of the cell has a higher concentration than the cytosolic side it is hypertonic. When it is lower than the cytosolic side it is hypotonic. When both sides of the membrane have equal concentrations, they are isotonic. The isotonic point is the point in which osmosis causes the concentrations of either side of the cell wall to reach an equilibrium (balance). The original experiment involved placing gummy bears in water and sugar and salt solutions (Gummy bear osmosis, 2022). The experiment was modified to further investigate the effect of varying NaCl concentrations on the mass of potatoes. …show more content…
Modifications to
The experiment we did was a lab to discover how “Miracle Gro” affected the germination of seeds. My group’s original hypothesis was that the seeds with the highest concentration of “Miracle Gro” would grow the most compared to the other seeds. However, after 8 days, the results were the exact opposite; the seeds that got 0% of “Miracle Gro” turned out to be the healthiest and tallest. By the third day, all five seeds, for the water solution, where sprouting. On the other hand, the solution with 4% “Miracle Gro” only had 3 seeds starting to sprout.
In walled cells, turgor pressure, the resistance to water movement by the cell wall, also affects osmosis. When cells are placed in a hypertonic solution, one with a higher solute concentration and lower water potential, water will move from the cell to the solution, causing the cell to be flaccid, or limp. As water diffuses out of a cell, it undergoes plasmolysis, in which the cell’s living part, including the plasma membrane shrinks and pulls away from the cell wall. On the contrary, when cells are placed in a hypotonic solution, one with a lower solute concentration and higher water potential,
OSMOSIS The outcome in the increase of sucrose absorption in the mass of Chips November 27, 2017 Candidate number: ftp678 BIOLOGY IA SL Research Question: If the chips are put under water in a sucrose solution. , will their mass decrease in a certain concentration of sucrose solution? Hypothesis: The increase of volume of sucrose solution will affect the mass of the chips to decrease since the water will possibly transport itself out of the cells. The larger the absorption of sucrose solution, the lower the mass of the chips will become.
Additionally, it was difficult obtaining a piece of rhubarb that was thin and particularly red, therefore the effect could not be best observed in the cells. Part B: Design your own experiment Parts of this practical were taken and slightly altered from the following link http://www.markedbyteachers.com/gcse/science/investigate-the-effect-of-surface-area-on-osmosis-in-potato-tissue.html Aim: To observe the effect different surface area: volume ratios have on osmosis in potato tissue. Hypothesis: If the potato has a larger surface area: volume ratio, the quicker osmosis will take place and the larger the mass will be at the end of the experiment, therefore the difference in mass of the potatoes from the start of the experiment to the end of the experiment will be larger. Additionally, the potato pieces left in a saltwater solution will decrease in mass, whereas the pieces left in water will increase in mass.
In our gummy bear lab experiment, we experienced osmosis, the water version of diffusion. My lab partner, Maggie, and I were given two yellow gummy bears. The first one measured at 10 mm in both thickness and width, and 21 mm in height. The approximate volume was 2,100 mm^3, and the mass was 2.567 grams. The second one was 11 mm in thickness, 9 mm in width, and 20 mm in height.
Exploration Title: Effect of Temperature on rate of Osmosis Submitted By: Abdulkarim Kamal Date Submitted: October 19th 2015 Subject: Biology HL Teacher: Mr. Nick Aim: This is an investigation to determine the relation between temperature of a solution (sucrose) and the rate of osmosis Scientific Context: Osmosis is defined a passive transport process in which a fluid diffuses across a semi-permeable membrane, from an area of high solute concentration to an area of low solute concentration and vice-versa. There are various factors that could potentially influence the rate of osmosis; these factors include volume, concentration, and temperature. If all external factors that may interfere with rate of osmosis are controlled, the results will show equal amounts of fluid on both sides of the barrier (membrane); this is known as an “isotonic” state.
Osmosis is defined as the net movement of water across a semipermeable membrane. Osmosis can cause cells to swell and sometimes burst. We can see this property in the lab we did in class. When we put gummy bears in the water they grew up to 500% of their original size. This happened because the water was entering the cells, causing them to swell and increasing the size and mass of the gummy bears.
The Gummy Bear experiment illustrates osmosis, a type of diffusion involving the movement of water molecules through a semi-permeable membrane. The gummy bear represents the semi-permeable membrane. The area inside of the gummy bear had a higher solute concentration than the area outside of the gummy bear, so the water was moving. In situations like this, water tries to move from an area of high water concentration (or low solute concentration) to an area of low water concentration (or high solute concentration). The water moves around until it achieves an equilibrium.
When trying to move a substance across a biological membrane, a passive transport might need a little help from a membrane protein. There are several types of ways to make moving these molecules easy. They might be as easy as osmosis or diffusion.
Commonly, molecules found within a liquid or a gas will diffuse more efficiently , however, the process of diffusion is altered by a range of permeability, such as the size of the diffusing molecules, the composition of the molecules and the surface area to volume ratio of the substance that the object is disseminating into. The purpose of the experiment is to find out how the size of the surface area and the volume of a cell can effect the rate of efficiency of a cell diffusing into space. The agar cubes act as cells and the surface area acts as the cell membrane. Each group conducts the experiment so the class average data is as precise as possible.
The cell membrane regulates the deoxyribonucleic acid, enzymes, and it builds a pathways for any reaction such as metabolic. When waste products are present the cell membrane gets rid of it and the cell membrane allows important things inside . A great example of what the cell membrane allows in or out is water and oxygen. Specific molecules are only made to enter the cell which is also called semipermeable. Molecules can be passed by active transport or either passive transport.
Diffusion and osmosis are directly related by that they are the movement of molecules from a high concentration to a low concentration. The main difference being that osmosis is a special kind of diffusion in which water is the solvent and moves from a high water concentration to a low water concentration through a semipermeable membrane. Diffusion and osmosis is vital to living organisms as it is the process by which useful nutrients and other molecules enter the body cell and waste products, from processes such as respiration, are removed. Part A of our lab was meant to show the process of osmosis using cornstarch and iodine. We placed a plastic bag filled with starch and water into a beaker filled with water and iodine.
Protein meshwork lining the inner nuclear membrane providing structural support to the nucleus. F Cell membrane Selectively permeable regulating the passage of substances in and out of the cell and maintaining cellular homeostasis. G Mitochondrion Energy production in cellular respiration. H Cytoskeleton Provides mechanical resistance to deformation, enables cell movement, and intracellular transport.
Introduction When solutions have a lower concentration than the solution that is surrounding them, then that solution is known to be hypotonic. When solutions have a higher concentration than the solution that is surrounding them, then that solution is known to be hypertonic. When a solutions concentration has the same concentration as the solution that is surrounding it, then that solution is known to be isotonic. Osmosis is when molecules move from high concentrations to low concentrations with water. Diffusion is when molecules move from high concentrations to low concentrations.
Looking at the animal cell, and each part of the cell, they all have different functions. The different parts of the cell are called organelles, this is because they are all specialised individual part of the cell that have specific functions. These functions for each part includes: Nucleus – The Nucleus regulates all of the activity in the cell. It is made up of a double membrane nuclear envelope, which encases it, and the nucleoskeleton, which supports the cell.