Diffusion And Osmosis Lab Report

1. Cell Membrane - A cell membrane in a cell is like the turnstiles and gates of a baseball stadium. The cell membrane is selectively permeable and the turnstiles or gate only let people with a ticket into the stadium

Obtain a small sample of the red epidermal cells from the stalk of the rhubarb by carefully peeling away the layer with forceps.

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?

This lab uses a lake simulation to study how the addition of nutrients and toxins can affect the lake, its inhabitants and the surrounding area. There is a strong focus on the addition of Phosphorous and added toxins because both are key elements in growth in lakes. The Virtual lake includes these five simulated species; green algae, cyanobacteria, bosmina, daphnia, and trout. There are two types of phytoplankton in the lake model, green algae and cyanobacteria. Green algae are a very diverse group that are photosynthetic, aquatic, plant like organisms that have a very simple reproductive structure. Green algae growth is a healthy and natural part of a lake’s ecosystem but the addition of nitrogen and phosphorus from fertilizers and other pollutants can cause an excessive growth problem for some lakes.

Cell membranes are the semi-permeable membrane that surrounds all cells. It separates the extracellular environment from the intercellular environment. It is a phospholipid bilayer which contains various proteins, lipids and carbohydrates all serving different purposes. It is this structure which allows for the transport of nutrients, proteins and water. (Nature.com, 2014). Through extensive testing it has been found that small alcohols, specifically ethanol can increase the fluidity and membrane permeability of the phospholipid bilayer (Patra et al, 2005). The aim of the experiment was to test what effect that ethanol solution would have on the membrane

In this lab we used two processes called Diffusion and Osmosis. Diffusion is the movement of molecules from areas of high concentration to areas of low concentration. Diffusion is a process that requires no energy and involves smaller non-polar molecules. In Figure 1 you can see the molecules spreading throughout the glass from the area of high concentration, so that the areas with low concentration are filled evenly as well. The other process was osmosis. Osmosis is the diffusion of water through a membrane from an area of high contraction to an area of low concentration. Osmosis happens in three different environments. Osmosis is like diffusion in it requiring no energy.

Based on the data and the recorded observations, my hypothesis is correct. When a solution is hypotonic, this causes the cell to swell, because there are more water molecules on the inside of the cell. If positive feedback continues, the cell will eventually burst. When a solution is hypertonic, this causes the cell to shrink, because there are more water molecules on the outside of the cell. Over time, the cell will start to function poorly (“Difference between Hypertonic, Hypotonic, Isotonic Solutions”). Therefore, the cell needs to maintain its internal environment through osmosis. In a hypotonic solution, osmosis allows water molecules to move from the inside of the cell to the outside, so as to keep the concentrations balanced. In a hypertonic

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. I used the measurements and compared them again with the Antibiotic Susceptibility zone chart. I was able to determine whether the

In this lab I will be exploring how temperature impacts the rate of osmosis by placing pieces of potato of equal size in solutions of different temperatures and observing the change in mass of potato after a given period of time. The change in mass will indicate the rate of osmosis.

This experiment is an attempt to investigate the amount of water potential across root storage plant species. The root storage plant species that shall be used are the carrot and the potato and the method that shall be used is known as Chardakov’s method. Water potential is the tendency of water to enter or leave a cell. Water moves from an area or region of low water potential to an area of high water potential. It is important to note that the highest water potential is 0(the water potential of pure water) and the other water potential values are in negative numbers .

Cell membranes are the semi-permeable membrane that surrounds all cells. It separates the extracellular environment from the intercellular environment. It is a phospholipid bilayer which contains various proteins, lipids and carbohydrates all serving different purposes. It is this structure which allows for the transport of nutrients, proteins and water. (Nature.com, 2014). Through extensive testing it has been found that small alcohols, specifically ethanol can increase the fluidity and membrane permeability of the phospholipid bilayer (Patra et al, 2005). The aim of the experiment was to test what effect that ethanol solution would have on the membrane

The overall project goals and central questions that has to do with the project is mostly trying to determine the isotonic concentration of the salt in potato roots and the use of the ideal soil salt conditions for the potato plant growth. In part 2, we had to test the enzyme activity that is in the was involved in the potato, so we can also determine the ideal soil pH conditions for the potato plant growth. In part 3, we were able to test absorb the leaf pigment at various wavelengths that determine the optimum light absorption conditions and was able to make recommendations for the light conditions that would be used un greenhouses.

In this experiment it will be analysed the damage alcohols can have on biological membranes. Membranes are made up of lipids and proteins. Membranes usually help maintain the balance in a cell as it holds all the cellular materials. There are various membranes and all have a variation of functions.

What are effects of the volume of a potato and the amount of weight it loses when placed in salt solution?

It justifies the idea that increasing the concentration of sucrose does in fact speed up the rate of osmosis, an therefore increase the mass of the Visking tube. This happens due to the water molecules moving from a high water concentration to a low water concentration. Another reason why this hypothesis is correct is because sucrose particles are too large to go through the membrane therefore the sucrose does not diffuse into the water. According to the mean graph there is a clear outline that indicates constant acceleration, which justifies that the increase of the independent variable affects the dependent