Incipient Point of Plasmolysis Lab

I obtained the results from the experiment supported my predictions because as the the concentration Na+ Cl- was increased from 5 mM to 10 mM (by adding more Na+ Cl-), the osmotic pressure also increased. However, after the membrane was changed to 50 MWCO, the Na+ Cl- molecules could diffuse easily through the membrane and did not caused an increase in osmotic pressure.

The cell membranes are the utmost essential organelle that surrounds all living cells. Its purpose is to control what goes in and out of the cells and is accountable for the various other properties of the cells as well. The nucleus and other organelles also have membranes that are practically indistinguishable. Membranes are organised in a mosaic arrangement, comprised of carbohydrates, proteins and phospholipids. This can be seen in Figure 1. The objective of this indirect examination is to study the causes of various solvents and conducts on live beetroot cells. The reason why beetroot cells have been selected for this experiment is because they have a big membrane-bound central vacuole, as seen in Figure 2. The red colour anthocyanin, which provides the beetroot its bright colour is located in the vacuole. The cell membrane encloses the whole beetroot cell. The anthocyanin cannot leak out if the membranes stay unharmed. The red colour can escape if the membranes are hassled or broken.

The use of multiple test tubes and Parafilm was used for each experiment. Catechol, potato juice, pH 7 phosphate buffer, and stock potato extract 1:1 will be used to conduct the following experiments: temperature effect on enzyme activity, the effect of pH on enzyme action, the effect of enzyme concentration, and the effect of substrate concentration on enzyme activity. For the temperature effect on enzyme activity, three test tube were filled with three ml of pH 7 phosphate buffer and each test tube was labels 1.5 degrees Celsius, 20 °C, and 60 °C. The first test tube was placed in an ice-water bath, the second test tube was left at room temperature, and the third test tube was placed in approximately 60°C of warm water. After filling the test tubes with three ml of the

3) The mass of the potato cells would decrease, since the NaCl is a higher concentration than theH20 molecules inside the potato cells. So, the potato’s cells will evacuate and go into the surroundings, making it shrivel. This is known as a hypotonic solution.

Purpose: The purpose of this lab is to familiarize you with osmosis and, specifically, what happens to cells when they are exposed to solutions of differing tonicities.

The Osmosis and Diffusion lab was conducted to provide us with information on how built up mucus affects those conflicted by the recessive genetic disease, Cystic Fibrosis., due to a mutation to the membrane regulating chloride (Cl-). This mutation prevents the Cl- from leaving the cell causing the amount of sodium (Na+) in epithelial cells, which results in extreme mucus on the lungs and airways causing this disease to be fatal if not treated but treatment does not equate to a long lifetime. During the lab we took the data from three parts: Diffusion, Osmosis in an Elodea Cell, and finally the Role of Osmosis in Cystic Fibrosis. During Part 1 we looked at diffusion across a semipermeable membrane for starch and glucose, which resulted in both having a negative solution when placed in a semipermeable membrane. Then we looked at osmosis in the Elodea Cell to watch for the occurrence of Plasmolysis, when a cell’s plasma membrane pulls away from the cell, and how a plant cell is affected by both hypertonic and hypotonic solutions. Finally, we observed the role of Osmosis in Cystic Fibrosis using dialysis bags to represent a normal cell and a Cystic Fibrosis cell with the normal containing 1% NaCl while the Cystic Fibrosis bag contained 10% NaCl. After we ran the experiment, we looked at the Percent Change in Mass and compared them after 30 minutes. We found that Cystic Fibrosis cells didn’t change mass as much as the normal cell ending with a change in mass over -1%. The

Aim: To investigate how effect of Detergent Concentration (cont.) has on Membrane permeability of Beetroot cells. Hypothesis: I predict that as detergent concentration increases, the solution will become less clear, plus mass increases. The increases in mass will indicate that the water potential of the Beetroot cell is lower than that of the surrounding sucrose solution. The Beetroot discs will become flaccid and decrease in mass if the water potential of the surrounding solution is lower than the water potential inside the beetroot cell.

The procedure of this lab is to determine if liver and potato cells contain natural buffers that resist large change in pH as 1. NaCl or 1. NaOH are added to the solution.

The cell membrane (Plasma membrane) functions to provide cell support, cell stability and control entry and exit of materials from the cell. This study was conducted to test the effects of environmental conditions such as the on beet root cell membrane (Beta vulgaris). Five trials using varied pH concentrations were tested and absorbance rates were monitored. The experimental results showed that the protein function decreased sequentially when the pH decreased. This allowed the betacyanin dye to leak out which created the color that was needed to determine the intensity and therefore the effect of the circumstances. This supported the hypothesis that the more acidic or basic the environmental condition around the beet cell, the more permeable the, membrane indicated by color intensity. Pigment leakage in the solution was analyzed by using a spectrophotometer.

A very carefully regulated process is solute concentration. If there is a sudden increase in water which enters the extracellular fluid, sodium ions will then contribute less to the extracellular solute concentration as the ratio between water and solute has now changed. Osmolality is the amount of solute in a kilogram, hence the osmolality in the extracellular space has also decreased.

I have accepted my hypothesis because of the results of the data from this lab. In

Finally, it could also be a hypertonic solution which is when there is a higher concentration of solute in the solution than in the cell and therefore the water leaves the cell. This make the cell plasmolyzed or “shrunken”. In our experiment this means that the potato cell would

In this lab we found out that the dialysis bag contained more fluids inside it. This can happen because sucrose is small enough to pass through the selectively permeable membrane. Some errors that might have been encountered during the lab could have been the fact that some of the dialysis bags were not tightly tied with the dental floss, or that the wrong substance was used. Another possible source of error was if the carrot strips had been dehydrated from the beginning of the experiment or were already

Experiment 1 & 2: The DNA concentration was 60 ng/µL (6.00*10^4 ng/mL). The total yield was 0.6 ng (60 ng/µL DNA /100 µL H2O). The DNA sample was divided by 100 µL instead of 25 µL of H2O because the sample was diluted 4 times.

Making the onion tip root cell slide was successful. Our results supported the hypothesis because we saw cells in the onion root tip in prophase, metaphase, and anaphase. As we went up in power objectives, each phase of the cell became more definitive. The cell root was a great indicator of the structures of the different cycles of the cell. This is important because we will be prepared for future labs working with the microscopes and can now adjust it for the best view of the slide. We practiced working with the compound light microscopes and different phases of the cell cycle. Onion root tips are useful to observe mitosis because the cells are frequently diving as the root grows. So when we stained the cell, we caught many cells in different phases. The significance of this lab was to better understand the process and stages of mitosis and meiosis and compare and contrast the mitotic process in plants and animals. We grasped the concepts of what the chromosomes look like, and what they look like in each step of the processes. Having read much about mitosis and meiosis, seeing these cells was the real application of describing and understanding the stages.