Objective- The objective was to determine the effect of salt water on a red onion cell membrane, but we are more focused on the actual cells.
Introduction- The purpose of this experiment was to see what happens to onion cells when salt water is added. Before I get into the details of this experiment, let’s discuss the differences and similarities of plant and animal cells. Plant cells and animal cells both have nucleus, cytoplasm and a cell membrane. However, plant cells have a cell wall; a cell wall is a rigid hard structure that helps plants like a human skeleton. Also they have a chloroplast; basically the melanin in the plant that makes it green. Also this is where the photosynthesis process happens, photosynthesis is how they convert carbon
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I bent the onion backwards so I could get the onion membrane, using my tweezers I took the membrane off the onion and placed it on my slide. I added regular water then put on my coverslip (to make a wet mount slide). I focused on the onion using the “Coarse adjustment knob” to make sure I could see what’s going on under the microscope. After looking at the regular water affected onion, I added a drop of saltwater. I observed my results at 4x objective then took notes then went to 10x & 40x and took notes and finally cleaned my station up.
Results- Before adding salt water the cells were exactly in place, you could see the cell wall and all the nucleus and cytoplasm. After adding the salt water the cell basically dehydrated, you could see how it shrunk up; the cell wall stayed in place but everything else just shrunk up and was more visible. After adding the regular water again the onion cells went back to normal; it rehydrated with the water so it looked how it did before because it rehydrated
The beet Lab experiment was tested to examine bio-membranes and the amount of betacyanin extracted from the beets. The betacyanin is a reddish color because it transmits wavelengths in red color and absorbs most other colors. The membrane is composed of a phospholipid bilayer with proteins embedded in it. The phospholipid bilayer forms a barrier that is impermeable to many substances like large hydrophilic molecules. The cells of beets are red and have large vacuoles that play a big role for the reddish pigment. This experiment aimed to answer the question, “How do cell membranes work?” The hypothesis we aim to test is: Cell membranes work as a fluid mosaic bilayer of phospholipids with many embedded proteins. We predicted that the 50% Acetone will break down the most betacyanin. Our hypothesis was proven wrong by our data collected. We could test our predictions by doing the experiment multiple times and compare the
Experiment #1: The purpose of this experiment is to investigate the effects of baking soda and light intensity on the rate of photosynthesis of green spinach leave through the observation of floating disk.
Conclusion In my conclusion, the potatoes with the lowest concentration gained the most mass, and would become hard relating back to the Turgor theory I stated earlier. In contrast to this, the potatoes in the most concentrated solution lost the most weight thus becoming plasmolysed and limp also relating back to the background I have mentioned earlier. Evaluation In general the experiment was succesful the results were consistent and also were in accordance with the theories made at the start.. The experiment could have been improved by: · More subjects used instead of potatoes · More potatoes · Wider time ranger · Different molarities Using this variety of methods could have improved the experiemnt, however I was generally satisfied with the results of this osmosis experiement.
The experiment is aimed at giving a better understatement of osmosis process and the different conditions in which osmosis occurs.
Osmosis is the facilitated diffusion of water across the cell membrane of a cell. The inside layer of the cell membrane is hydrophilic, meaning water cannot easily pass through the membrane. The cell membrane has to have aquaporins, which are water channel proteins, that move the water across the membrane. If there is a water and salt solution outside the cell, the salt can enter the cell by diffusion, but the cell membrane is not permeable to the water. Because there is more solute solution inside the cell, there is less water. The aquaporins move the water across the membrane until equilibrium is reached.
If a plant cell is places in a hypotonic solution the cell has a lower water concentration to that of the solution. Water will move into the cell by osmosis from a high water concentration outside the cell to a lower water concentration inside the cell through a selectively permeable membrane. The cell becomes turbid
So what is happening is water is moving from a high concentration, i.e. a dilute solution to a more concentrated solution. Preliminary Work on Osmosis I am going to test carrots in a small osmosis experiment to see how the experiment works with carrots and salt solution and water. Variables 1) Temperature - Keep the same 2) Number of days left soaking - Keep the same 3) Size of beaker - Keep the same 4) Size of carrots - Keep the same 5) Concentration of salt solution -
If we put the potatoes in different concentrations of seawater (0%, .4%, .8%, 1.2%, 1.6%, and 2%) then the potato put in the highest concentration of seawater (2%) will begin to discolor and fall apart while the potato put in the lowest (0%) concentration of seawater won’t discolor and fall apart because the seawater with the 2% concentration will diffuse into the potato causing it to break down and discolor faster than the potato in the lower concentration of seawater.
Two members of the group were instructed to visit the laboratory each day of the experiment to water and measure the plants (Handout 1). The measurements that were preformed were to be precise and accurate by the group by organizing a standardized way to measure the plants. The plants were measured from the level of the soil, which was flat throughout all the cups, to the tip of the apical meristems. The leaves were not considered. The watering of the plants took place nearly everyday, except for the times the lab was closed. Respective of cup label, the appropriate drop of solution was added to the plant, at the very tip of the apical meristems.
The “Fast Plant” experiment is an observation of a plants growth over the span of twenty-eight days. The objective is to observe how plants grow and use their resources throughout the span of their life. In our lab we observed the Brassica rapa, a herbaceous plant in the mustard family which has a short cycle which makes it a perfect plant to observe in this experiment. Like other plants the Brassica rapa must use the resources in the environment to create energy to complete itʻs life cycle and reproduce. By observing the plant it is easy to see in what organ or function the plant is using itʻs energy and resources and if overtime the resources switch to other part of the plants. By conducting this experiment we are able to observe where and how plants allocate their resources throughout their life by harvesting plants at different points in their life.
Water passes into cells through a special type of diffusion called osmosis. Water molecules diffuse through the membrane from a weak solution into a strong solution until the concentration is the same on both sides. A membrane that allows only certain molecules to pass through is called a semi-permeable membrane. In a plant, water passes from a weak cell sap solution to an adjoining cell with a stronger solution, as water passes in, the volume of the sap vacuole increases. When a full sap vacuole presses against the cell wall, it is said to be turgid. If water that is lost is not replaced the sap vacuole shrinks and pulls on the cell wall, the cell becomes flaccid; this is known as plasmolysis.
(Cliffnotes) Osmosis played a really big role in the second part of the experiment. One of the beakers was filled with water and so was one of the dialysis tubes and both reacted with sucrose. When particles move through the membrane, whether they go in or out, the cell will either begin to shrink or grow, and can grow so much that it bursts. If a solution gains water it is called a hypertonic to the solution on the outside. If the opposite happens then the solution is hypotonic. When an equal amount of water particles are transferred between both solutions then they are both called isotonic solutions. (Lab notes) Dialysis is the process in which particles, that are different sizes, are separated using a selectively permeable membrane. In the experiment we used the dialysis tubes to test the permeability of water, sucrose and
Osmosis in Potato Tubes Osmosis: Osmosis is the movement of water molecules through a semi-permeable membrane from a high concentration to a low concentration. Diagram: [IMAGE] [IMAGE] Aim: To see the effects of different concentration of sugar solution on Osmosis in potato tubes. Key factor: In the investigation we change the sugar solution from: 0%-10%-20%-30%-40%-50% this is the independent variable; the dependant variable is the change in mass. Prediction: I predict that all the potato tubes in pure water or low concentration sugar solution will swell because water enters their cells by osmosis.
Through the osmosis experiment, it was clear that water moved into the cell due to a lack of water and an excess of solute; in the environment, there was an excess of water and a lack of solute. The biochemical testing relayed information about what minerals, particles, elements, or
When plants such as seaweeds or others that grow under water, their parts are supported on all sides by hydrostatic pressure. There is not much difference in the density between plant cells and their surrounding liquid environment. Aquatic plants do not require significant structural support; their cell walls only contain polysaccharides, c...