Neutral Red Dye Lab Report

The concentrations and absorbances of the red and blue dyes were used to find the concentration of the purple dyes. From the graph of the blue dye, the linear equation for absorbance was y = mx + b. From that formula came the equation y = 7.915 x 104 (x) + 0.02489, where y represents absorbance, m is slope, x is concentration/molarity, and b is the constant/y-intercept. The same set up was performed for the red dye, but the equation produced was y = 1.045 x 104 (x) +.001298. The equations found when graphing absorbance vs. concentration were used to find the concentration of the purple dyes. The absorbance for purple dye 3 on the red wavelength of 470 nm equaled 0.149 and 0.818 for the blue wavelength of 635 nm. For purple dye 1

The purpose of these experiments is to examine the driving force behind the movement of substances across a selective or semiperpeable plasma membrane. Experiment simulations examine substances that move passively through a semipermeable membrane, and those that require active transport. Those that move passively through the membrane will do so in these simulations by facilitated diffusion and filtration. The plasma membrane’s structure is composed in such a way that it can discriminate as to which substances can pass into the cell. This enables nutrients to enter the cell, while keeping unwanted substances out. Active

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.

Therefore, more of the red pigment in the beetroot would leak as the lipids control the substances that enter and leave the cell membrane.

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.

Lab six requires students to observe the effects of pH and enzyme concentration on catecholase activity. Enzymes are organic catalysts that can affect the rate of a chemical reaction depending on the pH level and the concentration of the enzyme. As pH comes closer to a neutral pH the enzyme is at its greatest effectiveness. Also at the absorbance of a slope of 0.0122 the enzyme is affected greatly. The pH effect on enzymes can be tested by trying each pH level with a pH buffer of the same pH as labeled as the test tube and 1mL of potato juice, water, and catechol. This is all mixed together and put in the spectrophotometer to test how much is being absorbed at 420nm. As the effect on enzyme concentration can be tested almost the same way. This part of the exercise uses different amounts of pH 7-phosphate buffer and potato juice, and 1mL of catechol mixed together in a test tube. Each substance is put in the spectrophotometer at a wavelength set tot 420nm. The results are put down for every minute up to six minutes to see how enzyme concentration affects reaction rate. The results show that the pH 8 (0.494) affects the enzyme more than a pH of 4 (0.249), 6 (0.371), 7 (0.456), and 10 (0.126). Also the absorbance is greatest at a slope of 0.0122 with test tube C that has more effect on the reaction rate, than test tube A, B, and D.

A major determinant of diffusion in a biological system is membrane permeability. Small, uncharged molecules pass through cellular membranes easily, while most and/or charged molecules cannot pass through the membrane. The movement of water across a selectively permeable membrane, like the plasma membrane

Within the experiment, pure catechol was mixed with different concentrations of catechol oxidase and the rate at which each solution produced benzoquinone was measured. The amount of benzoquinone made throughout the trials was measured by using a colorimeter to measure the level of “brownness” of the liquid. The colorimeter worked by shining a light through the liquid and then measuring that light on the other side to see how much of it was absorbed. In this experiment, absorbance of blue light was measured because blue light is absorbed by the color brown. The amount of blue light absorbance was measured every 15 seconds for five minutes. Because enzymes speed up reactions, more enzymes would cause the reaction to be even faster.1

The values of color absorbance are effective because color absorbance has a linear relationship with concentration values, which in turn, allows us to easily find concentration values for many solutions. Beer’s law describes this phenomenon since the absorbance is directly proportional to concentration. We observed that as the color absorbance increased, the concentration of the FeSCN2+ complex ion increased. This is because as the FeSCN2+ concentration increases, the blood-red color becomes darker due to more presence of the blood-red FeSCN2+ ion. Therefore, the color absorbance increases because there is more blue color absorbed by the darker red color. We then graphed the absorbance and concentration values and created a line of best fit. Using the line of best fit, we were able to predict the equilibrium concentrations of the FeSCN2+ solutions and find the change required to reach equilibrium. Since we already knew the initial concentration of FeSCN2+ and since we already found the equilibrium concentration of FeSCN2+, we can calculate the change in equilibrium. Using this data, we were able to calculate the equilibrium concentration of all of the species in this lab, since we already knew the change from the initial concentration to the equilibrium change. Q is less than K because there was no initial concentration of FeSCN2+, but after the system reached

Every cell transports materials in and out throught something called a membrane. There are many different methods of transport in the cell Saccharomyces cerevisiae (Serrano, 1977) We want to know does adding higher concentrations of azide more effectively block dye transport? We tested the transport of dye in yeast cells with a metabolic inhibitor. When we did this we showed no difference in the absorbance between different azide solutions, and our control. From this we concluded that azide has no effect on the transport through a yeast cell membrane.

The establishment of electrochemical gradient is one of the driving forces for ion movement across the cell membrane. Cells are usually negative and surrounded by positively charged extracellular fluids. All transport processes across cells impact the chemical gradients. There are two primary transport processes that affect electrical gradients, electroneutral carriers and electrogenic carries. Electroneutral carries transport uncharged molecules or exchange an equal number of particles with the same charge across the membrane, ultimately not changing the overall elecrtochemical gradient. Electrogenic carriers result

Turnips and horse radish roots are rich source of this enzyme. In this experiment, we would carry out a reaction between hydrogen peroxide and guaiacol which is colorless dye, using peroxidase as a catalyst, to produce water and an oxidized form of guaiacol which is brown. The formation of brown color would serve as an indicator that the breakdown of Hydrogen Peroxide took place. The enzyme activity would be directly proportional to the brown color intensity. The color intensity would be measured using a spectrophotometer and standardized to find the corresponding concentration for each absorbance unit.

A cell needs to perform diffusion in order to survive. Substances, including water, ions, and molecules that are required for cellular activities, can enter and leave cells by a passive process such as diffusion. Diffusion is random movement of molecules in a net direction from a region of higher concentration to a region of lower concentration order to reach equilibrium. Diffusion does not require any energy input. Diffusion is needed for basic cell functions - for example, in humans, cells obtain oxygen via diffusion from the alveoli of the lungs into the blood and in plants water

All cells contain membranes that are selectively permeable, allowing certain things to pass into and leave out of the cell. The process in which molecules of a substance move from an area of high concentration to areas of low concentration is called Diffusion. Whereas Osmosis is the process in which water crosses membranes from regions of high water concentration to areas with low water concentration. While molecules in diffusion move down a concentration gradient, molecules during osmosis both move down a concentration gradient as well as across it. Both diffusion, and osmosis are types of passive transport, which do not require help.

When defined through the visual confirmation, the spectators were able to see for every net consumption of “0.94 H+ there is an ATP formed through the experiment with a pH 8.0, pMg 2.52, 0.05 M ionic strength and 20oC.“ This establishes that the efflux of H+ in the thylakoid lumen was obtained from the decay of the proton gradient. As a result, to improve the H+ levels one must add more imidazole, which will increase the