... (4x, 10x, 40x) Part 2: 1) Repeat the same lab procedure as you did with soaking onion skin cells in tap water last day, but now using the onion and soaking it into saltwater. 2) Prepare a wet-mount slide for the onion skin cell done by your teacher. 3) Add iodine to the onion and place a cover slip on top of the onion. 4) Examine the slide under all magnifications and sketch Proper Biological Diagrams for each power. (4x, 10x, 40x) Hypothesis: If tap water is added to the onion skin cells then the water will absorb and swell up because, osmosis is occurred and it becomes completely inflated. If saltwater is added to the onion skin cells then the cells would wrinkle up and probably shrink because, once the onion is placed in salt solution, it will dehydrate since it’s hypertonic. The water would leave the cell by diffusion to get an osmosis balance. Observations: Quantitative Variables: * Amount of salt * Amount of water * What time you start the experiment * Where you place the onion * What temperature was the onion placed in before * How much iodine you drop on the onion skin * How long did you place the onion skin in either salt or tap...
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...Change in Potato Cells Due to the Effects of Osmosis (AYE YO POTATO! HOW MUCH OSMOLARITY YOU GOT?) Introduction: The purpose of this experiment was to determine the osmolarity of a potato. Osmolarity is defined as the solute concentration expressed as molarity. Lerner and Lerner (2008) define osmosis as the movement of water across a membrane that is selectively permeable. Osmosis is important in plant cells because it plays a role in regulating guard cells, which are cells that are on the surface of a plant’s leaves and control the opening of the stoma. When the stoma is open, it increases the water movement out of the plant by a process called transpiration. When there is a shortage of water, the guard cells well get smaller and close the stomata, and the transpiration process will move slower. The osmolarity would be tested with solute concentrations ranging from 0.0 M to 0.6 M. The concentrations increased 0.1 M each time and the solute used was sucrose. The goal of this experiment was to determine which concentration had the least effect on the potato after being incubated. This information helped us estimate the osmolarity of the potato tuber tissue. Our group hypothesis is that the osmolarity of the potato will have the concentration with the 0.1 M solution. This hypothesis is based off the predicted outcome that smaller molarity concentrations will have the least effect on the potato. The more solute added to a solution decreases the concentration of water in most cases (Kosinski)...
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...Diffusion And Osmosis Introduction: There are several valuable aspects of this lab that must be understood before it is conducted. The first of these concepts is called diffusion. Molecules are constantly moving and as they are moving they tend to move from areas of higher concentration to areas of lower concentration. Diffusion can be defined as the net movement of molecules from higher to lower concentrations. One example, of diffusion is when an item like perfume is opened in a room. Shortly after it is opened the smell can be detected throughout the entire room. Diffusion can occur through a membrane such as that of a cell which explains how something can enter the cell. One special type of diffusion is called osmosis or the diffusion of water. Osmosis describes how water moves through a membrane from areas that have high water potential to areas that have lower potential. Water potential is defined as the measure of free energy of water in a solution. Biologists use this term to help describe why water moves from one area to another. Water potential can be affected by two major aspects pressure and the amount of solute. Water potential can be calculate by the pressure potential added to the solute potential. In order to calculate the solute potential one must multiply the ionization constant, the molar concentration, the pressure constant, and the temperature. When looking at a solution one can categorize it into several different relationships based...
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...Osmosis Is Serious Business! by Troy R. Nash Department of Biology Presbyterian College, Clinton, SC Questions-Too Much of a Good Thing 1. The extra fertilizer created a hypertonic environment around the roots of the corn ____/ 2 pts. What sort of environment (hypotonic, hypertonic, isotonic) did the extra fertilizer create around the roots of the corn? 2. The extra fertilizer caused the soil to become hypertonic which cause water to diffuse out of the corn into the soil. This caused the crops to die from lack of water. ____/ 2pts. Keeping in mind your answer to the previous question, what do you believe caused the corn plants to wilt and eventually die? 3. If Michael would have told his dad what he had done, two things could have possibly been done.. One option would have been the removal of as much of the extra fertilizer as possible to reduce the chance of the fertilizer becoming hypertonic. The other option would to be to overwater the crops so the environment would be isotonic and no diffuse would take place because of the equal concentrations of the solutions inside and outside of the plant cells. I think just telling his father would have saved a lot of heartache and trouble. ____/ 2 pts If Michael’s mistake had been caught earlier, is there anything that could have been done to prevent the corn from dying? Questions-Too Little Too Late 1. The distilled water cause the patient’s bloodstream to become a hypotonic environment . ____/2pts. What problem did...
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...Problem and Background Information The experiment was: the effect of salt water on the growth of plants. One group of plants well watered with normal water and the other group will be watered with saltwater (More information about groups and variables under heading: Variables and Groups, that is located later in the report). In previous tests, the plants that contained saltwater did not grow a lot and the salt had a negative impact on the plant. Osmosis is one of the factors that have a negative effect. When salt is present in the water, it tends to tends to pull out the water from the roots. The roots pull in the available water while the salt pulls out the water. Salt can also cause dehydration to plants, which can cause the plant to shrive and die....
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...Laboratory Exercise Osmosis and Diffusion “Osmosis and the Incredible, very Inedible Egg” **This is a fun thing to have your kids or significant other help with. Please note that this experiment takes several days to complete, so don't wait until the last minute to start!** I. Background: Osmosis is the diffusion of water molecules through a semi-permeable membrane. This is how water gets into and out of our cells. In this lab we will investigate the effects of different solutions on the water content of an egg. An egg will serve as our model of a cell. A. Remember, when comparing 2 solutions, the one with the greatest amount of stuff dissolved in it is called hypertonic while the one with the lesser amount of stuff dissolved in it is called hypotonic. Please get these terms straight in your mind before you start the experiment. B. Therefore, hypertonic solutions have less percentage of water in them than hypotonic solutions. Water, like everything else, moves from a greater concentration of itself to a lesser concentration of itself. C. In this experiment you will observe the movement of water into and out of an egg. To do this we will remove the minerals from the egg shell leaving only a membrane that is permeable to water. II. Supplies needed: 3 eggs 4 drinking glasses or clear containers Vinegar (about 2 cups) Foil or plastic wrap White Karo syrup (or any brand like it) Distilled water (actually...
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...Osmosis Experiment Diana Arrowood Grand Canyon University BIO-100L Biology Concepts September 16, 2011 Osmosis Experiment Directions Use the information below to complete the Osmosis Experiment. Materials 1 fresh baking potato Water Salt Four small containers (i.e., drinking cups or clear glasses) A metric ruler Methods and Procedure 1) Place 1 cup (236 ml) of water in each of the 4 containers. In 2 of the containers, add 1 tablespoon (14.8 ml) of table salt and mix well until dissolved. Label which containers have salt. Cut a fresh baking potato into 5 mm slices. Cut four rectangles 2.5 cm x 1 cm from the slices as close to the same size as possible. Measure the length and width of each rectangle in metric units and place one in each of the containers, keeping track of which measured slice went in which container. There will be two slices (duplicates) for fresh water and two for salt water. After 1 hour, remove and measure the length and width of each piece of potato and return it to the appropriate container. Note any physical changes. After 24 hours, remove and measure the length and width of each piece of potato. Note any physical changes in the potatoes and describe their appearance. Written Lab Report Introduction 1) Address the following questions: A) Define osmosis. Osmosis is the movement of solvent molecules through a selectively permeable membrane into a region of higher solute concentration, aiming to equalize the solute concentrations...
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...Solute Concentration of Potatoes Carmen Chen Blk: 7 December 14, 2013 Purpose: to determine the concentration of solute in potatoes cytoplasm. Materials and Equipment: refer to the lab sheet. Observations: | |Concentration of sucrose|Initial mass |Final mass |Percentage change in | |Test tube # |solution ( |(g) |(g) |mass | | |mol/L) | | |(%) | |1 |1.0 |3.0 |-0.9 |-30% | |2 |0.9 |3.9 |-1.2 |-30.8 % | |3 |0.8 |3.2 |-0.7 |-21.9% | |4 |0.7 |3.5 |-0.8 |-22.9% | |5 |0.6 |3.3 |-0.6 |-18.2% | |6 |0.5 |3.0 |-0.3 |-1% | |7 |0.4 |3.1 |-0.2 ...
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...Abstract: The rate of osmosis was examined through an experiment. Dialysis tubes were used to simulate a cell membrane. Solutions of 0.20 % and 0.40% sucrose were placed in each tube. The bags were placed into water and let to sit for three intervals of fifteen minutes. In the first bag that had no sugar solution, it had an osmosis rate of -.04 g/min. In the second bag that had 20 percent sugar solution, it had an osmosis rate of .09 g/min and the bag that had 40 percent of sugar solution had an osmosis rate of .11 g/min. What was concluded from the results is that the more percent of sucrose solution, the higher the rate of osmosis will occur and the lower the percentage of sucrose solution, the lower the rate of osmosis. Introduction: In order to understand the process of osmosis, proper terms must be defined. The first term was osmosis itself, osmosis is defined as the passive transport that refers to the diffusion of water across a selectively permeable membrane (Reece, 2009). Then of course, there are three different cases of osmosis which were defined. Hypertonic is a solution with a higher solute concentration. Hypotonic is a solution with a lower solute concentration. Isotonic is when the cells solute concentration is equal. The volumes were all made possible to increase or decrease via the plasma membrane, the plasma membrane defined as a flexible boundary between the living cell and its surrounding (Reece,2009) The dialysis tube represents the plasma membrane and...
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...What is dissolved oxygen? Dissolved oxygen alludes to the level of free oxygen not bonded to any existing molecule in the water or other liquid substances. It is an important parameter in assessing water quality because of its influence on the organisms living within a body of water. In limnology (lakes studies), dissolved oxygen is a crucial factor second only to water itself. A dissolved oxygen level that is too high or too low can harm aquatic life and affect water quality. Non-compound oxygen, or free oxygen (O2), is oxygen that is not bonded to any other element. Dissolved oxygen is the existence of these free O2 molecules in the water. The molecule of oxygen bonded in a water molecule (H2O) is in a compound and does not count toward dissolved oxygen levels (Rivsbech et al., 1988). Dissolved oxygen from the atmosphere Dissolved oxygen goes into the water through the air or as a byproduct of a plant. From the air, oxygen can slowly diffuse across the water’s surface from the nearby atmosphere, or be assorted in rapidly through aeration, whether natural or man-made. Water aeration can be brought about by wind (creating waves), fast-moving water, waterfalls, discharge of ground water or other systems of running water. Artificial sources of aeration differ from an aquarium air pump to a hand-turned waterwheel to a big dam. Dissolved oxygen is moreover produced as a surplus product of photosynthesis from algae, phytoplankton, seaweed and other water plants (Sherrard et al, 1979)...
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...The molecules move from areas of a high to a low concentration. But through will move across a partially permeable membrane (semipermeable membrane).The membrane can only allow some of the molecules to transfer across. The partially permeable membrane has openings small enough for water molecules to pass. So it is mean solute cannot through the membrane. There are three classifications of osmosis. Three classifications are isotonic, hypertonic and hypotonic. Isotonic ( iso = same, tonic = strength ) Equal concentration of solute on the outside and inside. The molecule going from the outside to the inside or from the inside to the outside. So they are not going have any net inflow or net outflow. So both inside and outside is the same concentration in the solution. Hypertonic ( hyper = more, tonic = strength ) - Hypertonic solution are going to pull fluid from inside of the cell out. - Lower concentration of water in cell - Higher concentration of solute in cell It has more solute on the outside. The water will want to rush out. Because there is more solute on the outside. After water rush, the cells are going to shrink. ...
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...Atichai Suwannapeng Pre Lab #6 Diffusion, Osmosis, and Tonicity Group #3 Section A3 Group Members: Laghu Shakya, Alex Maican, Kelvin Chen, Ziye Lin 10/18/2015 Abstract: In this lab we will be gaining an understanding of how transport in membranes work. This is important because in our semi permeable cell membrane the mode of movement relies on transport. Some methods of transportation for molecules are simple diffusion, facilitated diffusion, active transport, exocytosis and osmosis. The reason molecules tend to move around when dissolved in a solution is because all molecules display random thermal motion and have kinetic energy. Kinetic energy is what allows the molecules to diffuse down a gradient of high concentration to regions of low concentration until the distribution of molecules become equal and achieved dynamic equilibrium. The entire solution only becomes homogeneous when one of the several factors are reached: the size of the dye molecules, temperature of the solution, density of the solvent and concentration of the dye. Heat is what causes random motion of molecules and passively moves molecules in biological systems. However, we can’t see this movement with our naked eye. In order for us to see this movement, we must use a microscope to see the small particles move after collision, this is called the Brownian movement. When talking about the cell membrane we must understand that it is selectively permeable, which means it can choose what can pass through...
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...Fatmata Diffusion Abstract dialysis tubing is, made of cellulose because it’s a selectively permeable membrane. In this experiment, we are testing to see if the solution in the beaker moves into the dialysis bag. Which because of that, Introduction Diffusion and osmosis are two types of transport mechanisms. Diffusion is the movement of molecules from areas of higher concentrations to areas of lower concentration until the molecules are evenly distributed through the area. Osmosis is the dispersion of water. Our cells are capable of absorbing nutrients because, the cell membrane is selectively permeable (some molecules can diffuse freely through the membrane while others cannot). In this experiment we used dialysis bag as a model of the cell membrane. Our hypothesis was that the glucose will diffuse out of the membrane into the beaker filled with iodine solution. To demonstrate dialysis tubing we used water, starch and iodine. When starch and iodine react together they form a dark brown color. Materials Rubber band | Dialysis bag | Beaker | Glucose solution | Iodine solution | Water, thread | Methods * Cut a piece of dialysis tubing that has been soaking in water approximately 40 cm (approx. 16 in) long, Tie the end of the dialysis tubing with two or more knots. * Fill the bag halfway with glucose solution. And add 4 full droppers of starch solution to the bag. * Hold the open end close while you mix the content o the bag. Rinse of outside the bag...
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...Name: Amber Pitcher Exercise 1: Cell Transport Mechanisms and Permeability: Activity 1: Simulating Dialysis (Simple Diffusion) Lab Report Pre-lab Quiz Results You scored 100% by answering 4 out of 4 questions correctly. 1. The driving force for diffusion is You correctly answered: b. the kinetic energy of the molecules in motion. 2. In diffusion, molecules move You correctly answered: a. from high concentration to low concentration. 3. Which of the following dialysis membranes has the largest pore size? You correctly answered: d. 200 MWCO 4. Avogadro's number is a constant for the number of You correctly answered: b. molecules. 01/14/16 page 1 Experiment Results Predict Question: Predict Question 1: The molecular weight of urea is 60.07. Do you think urea will diffuse through the 20 MWCO membrane? Your answer : c. No, not at all. Predict Question 2: Recall that glucose is a monosaccharide, albumin is a protein with 607 amino acids, and the average molecular weight of a single amino acid is 135 g/mole. Which of the following will be able to diffuse through the 200 MWCO membrane? Your answer : b. both glucose and albumin Stop & Think Questions: The reason sodium chloride didn't diffuse left to right is that You correctly answered: c. the membrane pore size was too small. Glucose is a six-carbon sugar. Albumin is a protein with 607 amino acids. The average molecular weight of a single amino acid is 135 g/mole. There is no reason to run these solutes...
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...Lab 2 Cell Structure and Cell Transport-14 Name __ carson held__________________ Introduction: The cell is the basic unit of structure of all living organisms. The cell carries out the functions required for the organism to reproduce, protect itself, metabolize food, move, produce substances to support the entire organism. In this experiment, you will explore the cell membrane’s role in allowing materials to enter or leave the cell. This is a vital function of the cell membrane. Using the Physio Ex CD 9.0, you will be able to conduct experiments showing the important cell membrane processes of diffusion, osmosis, filtration, and active transport. The simulations will allow you to alter conditions to show the effect of concentrations, pore size, pressure, carrier, and ATP have on movements of materials through the cell membrane. Purpose: To conduct experiments showing the effects of concentration, ions, and particle size of movement through the cell membrane. Materials: Lab manual, PhysioEx 9.0 Procedure: Cell Transport Mechanisms and Permeability in the lab manual. You will also need the PhysioEx 9.0 CD for this lab. Read over exercise overview and introduction. Complete the following questions from the exercise as you complete the simulation exercises. Go to Exercise 1 Cell Transport Mechanisms and Permeability on the CD. Follow the directions and complete each part. Answer questions or fill in tables as...
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