Effect of Stress on Beet Cells

Originally, the absorbance measured for samples in –5°C and 70°C were 1.700 and 0.845; the concentrations were 425 μm and 180 μm respectively. However, because both of these absorbance readings were greater than the highest absorbance value in our standard curve (Figure 1), a calculation of diluted concentration for these two samples was necessary. Therefore, using the formula Cu = Cd/D where Cu = concentration of undiluted (original) sample, Cd = concentration of diluted sample and D = dilution (which is 1/5 in this experiment), we calculated that the diluted concentration for the sample in 5°C is 85 μm and for the sample in 70°C is 36 μm. As we inserted these data on the graph (Figure 2), concentration of betacyanin for samples in –5°C and 70°C still dominate in comparison to others. This sudden increase of concentration allowed us to understand that the tonoplast membrane is easier to be damage in extreme temperature.

This lab was performed to test the permeability of the cell membrane of a beet using various and extreme temperatures (high and low). The prediction of this lab is testing how much stress the cell membrane can withstand under different polarities and strengths of bonds using our understanding of the fluid-mosaic model. A spectrophotometer was used to calculate the absorbance of each variable after the beet was placed in each environment. When the lab was completed, the data stated that under each different reactant and condition the cell membrane showed multiple changes in tolerability of the beets.

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.

The purpose of this experiment was to alter the cell membrane of the beets, in a given fashion, so that we can test how much betacyanin was able to cross the cell membrane of the beet through various treatment. In which after we would test the absorbance level of each treatment, run it through excel and observe which treatment was most effective at getting betacyanin through the cell membrane more.

Test tube 1 and 2 didn’t show any color change. These two test tubes had lower levels of pH. Therefore, the enzymes could not change the starch to sugar.

When the beetroot sample is heated for a longer period of time, it is exposed to the vigorous and frequent vibrating molecules for a longer duration. This further disrupts the cell membranes making them more fragile, thus more pigment will leak out into the external solution. With more leakage of the betacyanin pigment, the % transmittance should be lower, indicating that the % of light that is able to pass through the beetroot solution should be less as duration heated increases.

Plasma membranes are the physical barrier of cells, which are selectively permeable to allow the passage of materials such as nutrients, gasses and waste products (Flinders University, 2015). The steroid cholesterol contained in the plasma membrane increases the membrane fluidity at higher temperatures (Blicher et al., 2009). Beta vulgaris contains a pigment called betalain, which leaches out of the tissue when there is an increase in membrane permeability, this causes the solution B. vulgaris is in to turn red (Flinders University, 2015). The aim of this investigation was to determine the effect of temperature on Beta vulgaris plasma membrane permeability.

The observation under the microscope of a cell of an onion skin soaked for 15 minutes in distilled water showed that the cell membrane was pressed against the cell wall. The cell

Time - Time is an important factor. When leaving the beetroot in the test tubes it must be ensured that they are in the water for exactly 20 minutes each. This will make sure that the same period of time is given for dye leakage to occur. To control this, putting the beetroot into each test tube two minutes apart will give enough time for them to be removed before the next test tube is ready to have its contents removed.

Cells in all living things have an outer layer known as the cell membrane. The structure of the cell membrane consists of the phospholipid bilayer organized by the arrangement of hydrophilic heads and hydrophobic tails. It is a selectively permeable membrane, where it divides the outer environment from the interior of the cell. It can control substances moving in and out of living cells. Certain molecules like gases, water, and food are permitted to pass the membrane through the method of diffusion. Diffusion refers to the process in which molecules move on the concentration gradient, where they move from an area of high concentration to an area of low concentration. A type of diffusion is known as osmosis. It is the diffusion of water moving across the selectively permeable membrane. In this lab, students will be using eggs to construct an experiment to get a better study on how osmosis works in a cell. The eggs will be soaked in vinegar solution to remove their shells to expose each inner layer that resembles a selectively permeable membrane. The egg shell is composed of calcium carbonate that would dissolves in acidic solution such as vinegar. In the chemical reaction, it releases carbon dioxide gas. After the removal of the egg shell, it will be ready to be able to construct the experiment.

The function of the cell membrane is to separate the cell from its environment and regulate the exchange of materials into and out of the cell. Along with the cell membrane, all cells have cytoplasm which is the substance composed mostly of water that fills the cell’s inner volume. The cytoplasm has three functions which are to provide a medium for organelles to remain suspended in, a site for many biochemical reactions, and aids in the movement of different cellular elements. In addition, both plant and animal cells have a network of tubular membranes within the cytoplasm of the cell, that can be either with a smooth surface (smooth endoplasmic reticulum) or studded with ribosomes (rough endoplasmic reticulum) and are involved in the transport of materials. Mitochondrion which break down sugar molecules into energy and a vacuole which stores food, water, and wastes are also organelles that are found in eukaryotic cells.

For lab 12, it is hypothesized that chlorophylls a and b are present in a plant leaf and contribute to the starch production in photosynthesis. Also, products of photosynthesis will be present in leaf tissue exposed to red and blue light wavelengths for several days, but a decreased presence in leaf tissue exposed to green and black light wavelengths. In lab 13, it is expected that since chlorophylls a and b are more polar and smaller molecules than the anthyocyanins and carotenoids, they will travel higher up the chromatography paper than the other pigments.

When put under stress, at some point materials begin to decline and perform poorly. Cell membranes are no different. The specific design and structure of plasma membranes allows for the regular function of cells through transportation, facilitating reactions, and several other tasks carried out by the cell membrane and endomembrane system. When put under physical or chemical stress, however, the plasma membrane begins to falter and will eventually become unable to perform its tasks, which are necessary to cell life. Using beet root tissue, the relationship between membrane performance and temperature was tested. 3 samples of beet were prepared and placed in a 50% methanol solution and exposed to temperatures above, below, and at room temperature. The membrane’s performance in repelling an unwanted solution in adverse conditions was measured by the amount of damaged membranes, which resulted in increases in released pigments. This lab’s hypothesis is: varying temperature will have an inverse effect on the membrane performance. The membrane will perform more poorly under increased heat than increased cold, but both changes in temperature will negatively affect the performance of the membrane. This will be measured by amount of light reflected by the spectrophotometer, reflecting how much pigment was given off, and therefore how many membranes were compromised. The independent variable is the temperature the sample is put through, and the controlled variables

Cells are the basic units of life. Everything alive consists of cells. In order for cells to perform their basic functions, it has to continuously seek homeostasis. This is done by structures within the cell. A structure within the cell is the plasma membrane, which regulates what enters and exits the cell. The cell membrane contains a phospholipid bilayer which causes the cell to have selective permeability; “allowing transport of some chemicals but not others” ( ). Specifically, the phospholipid bilayer allows for the movement of water, oxygen, and carbon dioxide. Conversely, it is not permeable to ions or polar chemicals. The phospholipid bilayer is in possession of hydrophilic and hydrophobic regions, which are the polar heads and tails, respectively. This is important because the head attracts water while the tail repels water, thus regulating the substances entering and exiting the cell. When substances pass through the plasma membrane, they use passive or active transport. Whether either transport type is used is determined by the concentration gradient, which is the difference of concentration between areas. In an active transport, the cell must use adenosine triphosphate, or ATP, which is produced by the mitochondria of the cell and is energy used by the body, because the substance is moving from a lower concentration gradient to a higher

The plasma membrane maintains dynamic homeostasis by separating the internal metabolic events of the cell from its external environment and controlling the movement of materials into and out of the cell. The membrane is a double phospholipid membrane, also referred to as a phospholipid bilayer, and has polar hydrophilic ("water loving") phosphate heads around the outside and non polar hydrophobic ("water fearing") fatty acid tails on the inside of the membrane. Slight variations in these structure of the fatty acids in the membrane alter the fluidity of the membrane. Phospholipids with saturated fatty acid pack more tightly, because of the nature of their single carbon bonds. This leads to a more rigid membrane. Unsaturated fatty acids, which have double carbon bonds, limit packing and result in a more flexible membrane. Cholesterol molecules distributed throughout the phospholipid bilayer provide some stability to the plasma membranes of animal cells. At higher temperatures the cholesterol molecules allow the membrane to be firmer, at lower temperatures they allow for flexibility.