Part A: Osmosis practical task Aim: To observe the effects of osmosis in rhubarb cells. Hypothesis: Water will be extracted out of the cells in the salt solution causing the cells to look different to the cells in the freshwater solution. Materials: Rhubarb Distilled water in a dropping bottle Salt solution in a dropping bottle Microscope, slides, and coverslips Forceps and razor blades or scalpel Paper Towel Method: Clean and dry a slide and coverslip.
Antibiotic Sensitivity of E.Coli and B.Cereus Cora Rebert March 28th 2024 Bio 350-Spring 2024 Collaborated with Emma Mayer and Krystie Webb. I have neither given nor received any unauthorized assistance in the completion of this work. Experiments described here were performed by me and/or my lab partner(s), and this report is entirely my own creative work.
1. How thick is an average cell membrane in mm? The average cell membrane is 0.000006 mm to 0.00001 mm thick. 2.
INTRODUCTION: In this experiment I was testing for antimicrobial sensitivity of Staphylococcus epidermidis by using the Kirby-Bauer Diffusion test. The three antibiotics utilized in this lab were: gentamicin, novobiocin, and penicillin. I determined the effectiveness of the antibiotic by observing and measuring the zone of inhibition for each antibiotic.
The dialysis experiment did not concur with the original hypothesis that all of the substances would be able to pass through the dialysis tubing into the surrounding water in the beaker. Sodium chloride and sugar did pass through the membrane while starch, was not able to pass through (fig. 7). These results show that sodium chloride and glucose (sugar) are small enough molecules to permeate the membrane, but starch is a much larger molecule and therefore was not able to get through. This is understandable because starch has a much higher molecular weight than the other two
Diffusion and Osmosis Lab Report By: Jettica Williams BIOL 1107 Lab September 21, 2016 Prepared for Mrs. Fulford Lab Course Page Break The cell membrane act as a roadblock for cells. The cell membrane has a very hectic job. It restricts the access to what comes in and what goes out. The bond the membrane shares with others is the idea of accountability.
Osmosis is a process where the solvent molecules pass through a semipermeable membrane from an area of high concentration to an area of low concentration until it reaches equilibrium. These solvent molecules, typically water, move freely. Carbon dioxide is able to move across the cell membrane through a process called simple diffusion. This works in a similar manner, carbon dioxide is able to move freely across the cell membrane from low to high concentration. When oxygen is breathed in, the red blood cells in the lungs have a low concentration of oxygen and a high concentration of carbon dioxide.
Osmosis Lab Report Research Question: How does the change in the concentration of a sucrose solution affect the process of osmosis in a potato cell by measuring its mass? Background information: 1 Osmosis is the process by which a liquid passes through a semi-permeable membrane, moving from an area with a high concentration of water to a low concentration of water. There are various factors that affect osmosis such as: concentration, surface area and temperature. The concentration of solutions can affect the rate of osmosis, as there is more difference in the concentration of the solutions, which means osmosis, will take place quicker. Surface area could affect osmosis based on the ease by which molecules can get through the semi-permeable
Title: Diffusion & Osmosis Purpose: The purpose of this experiment was to test the tonicity of the different solutions. Background: Diffusion and osmosis are both processes that occur within the plasma membrane. Diffusion is the process by which molecules intermingle as a result of kinetic energy. Osmosis is the movement of water across a semi-permeable membrane. Tonicity is also related to osmosis.
Biology Design Practical Joshua Edwards What are effects of the volume of a potato and the amount of weight it loses when placed in salt solution? Introduction This design practical uses a potato’s surface area to volume ratio to see what affects it has on osmosis in different concentrations. Osmosis is the movement of water molecules through a cell membrane into an area of a higher solute concentration. The movement goes the way of the solvent with more solute because the lower solute concentration is drifting through balancing the ratio of solute per solvent (En.wikipedia.org, 2018).
The Effect of the Molecular Weight of a Substance to its Rate of Diffusion Paulo E. Garcia Group 2 Sec U-7L October 16, 2014 ABSTRACT The rate of diffusion was tested by using a petri dish with agar-water gel and three drops of different solutions. These solutions were observed for thirty minutes and measured every three minutes. The different solutions used are Potassium permanganate with a molecular weight of 158 g/mole diffused the greatest distance among the three, Potassium dichromate with a molecular weight of 294 g/mole diffused the lesser than that of Potassium permanganate, and Methylene Blue with a molecular weight of 374 g/mole diffused the least distance.
In this experiment, the amount of water lost in the 0.99 gram sample of hydrated salt was 0.35 grams, meaning that 35.4% of the salt’s mass was water. The unknown salt’s percent water is closest to that of Copper (II) Sulfate Pentahydrate, or CuSO4 ⋅ 5H2O. The percent error from the accepted percent water in CuSO4 ⋅ 5H2O is 1.67%, since the calculated value came out to be 0.6 less than the accepted value of 36.0%.This lab may have had some issues or sources of error, including the possibility of insufficient heating, meaning that some water may not have evaporated, that the scale was uncalibrated, or that the evaporating dish was still hot while being measured. This would have resulted in convection currents pushing up on the plate and making it seem lighter by lifting it up
Various models and mechanisms for the solvent and solute transport mechanism through reverse osmosis membrane have been developed and proposed by a number of investigators and researchers. The flow of solvent through the membrane is defined in terms of flux as: The solvent flux of the permeate depends on the hydraulic pressure applied across the membrane, minus the difference in the osmotic pressure of the solutions of the feed and permeate side of the membrane which is written as. While the solute flux depends on the concentration gradient as: The membrane rejection is defined as the difference between the feed concentration and permeate concentration as: From the solvent and solute flux Equations.
The effect of the solution concentration of sodium chloride on diffusion in yam cores compared to the solution concentration of water Abstract The purpose of the experiment was to see if different solution concentrations had an effect on diffusion. Our group established a hypothesis that stated; sodium chloride will make the yam cores weigh less than in water. In order to start experimenting, we obtained 10 yam cores, weighed them and placed them in five cups that contained 50 mL of water.
Abstract New copolymeric membranes was offered for the efficient delivery of antibiotic drug using the synthesized chitosan–copoly(semicarbazide–formaldehyde–phenylhydrazine) blend membranes. The membranes were prepared by solution casting technique and characterized by elemental, spectral and scanning electron microscopy to establish the chemical structure and morphology. Scanning electron microscopy clearly reveals that the increased porosity in the polymeric network enables rapid swelling; leads to faster diffusion which facilitates effective drug release. The composition of chitosan content also governs the swelling behavior i.e. increased chitosan content showed excellent swelling behavior leads to profound drug delivery.
