Biological Membranes Lab Report

Question 4: List the 3 errors; • Adding too many drops of NaOH at the same time would affect the results because we can’t determine the exact equivalent point when the color changed. The results won’t be accurate and that will affect all the data that are dependent on the amount of NaOH to titrate. • Other error could be the hardness to notice a color change; we always use a white paper under the flask to determine when the color changes right away. And if we don’t use the white paper it will be hard to determine the color change and the amount of NaOH that was used to titrate it. • Also other source of error could be by not rising the burette with NaOH before we fill up with it, or it maybe they were rinsing it with a lot of NaOH which could affect the data recording for NaOH amount of titration.

That mixture was then filtered through a coffee filter. Nine test tubes were prepared in order to perform this dye coupled reaction. One contained 5.0ml of the potato and pH buffer mixture, 2.0 ml of hydrogen peroxide, and 1.0 of guaiacol to serve as a blank for the spectrophotometer. Four test tubes were filled with 2.0 ml of hydrogen peroxide and 1.0 ml of guaiacol, used for measurement by the spectrophotometer, each. The last four were filled with 4.0 ml of the potato and pH buffer mixture and 1.0 ml of peroxidase.

Chromatography Lab Riley Borklund Table 5, Seat 2A Lab Partners: Martin, Katherine, and Dakari Honors Biology, Mrs. Semaan January 5, 2016  Abstract: The purpose of this lab is to find what pigments are in a spinach leaf. The only pigments visible to the eye are chlorophyll a and chlorophyll b. We know this because chlorophyll reflects the green wavelength of light and shows us that it is present. We also, however, wanted to know what else is present in the spinach leaf.

From this research and literature the expected results of the experiment were to see an increase in membrane permeability, this result was observed. The study provides a brief insight into what kind of effects alcohol can have on cell membranes but it is limited. The results can be used to understand but not explain more practical applications, like human cells for example. Conclusion

Abstract The purpose of this experiment is to test for mitochondrial activity by isolating different organelles using the differential centrifugation process. Studying mitochondria is extremely important because they control the death and life of the cell by regulating the apoptotic signals (Frezza et al 2007). Also they are responsible for the metabolic reactions (aerobic respiration) and the production of ATP (Frezza et al 2007). Three hypotheses were formed based on my knowledge.

When you drink alcohol, it cannot be broken down in your liver. It will go to the rest of the body. The brain is one of the location that it can go. Alcohol does affect the brain. It can mess up the controls of the movement of the brain, and judgement.

Additionally, it was difficult obtaining a piece of rhubarb that was thin and particularly red, therefore the effect could not be best observed in the cells. Part B: Design your own experiment Parts of this practical were taken and slightly altered from the following link http://www.markedbyteachers.com/gcse/science/investigate-the-effect-of-surface-area-on-osmosis-in-potato-tissue.html Aim: To observe the effect different surface area: volume ratios have on osmosis in potato tissue. Hypothesis: If the potato has a larger surface area: volume ratio, the quicker osmosis will take place and the larger the mass will be at the end of the experiment, therefore the difference in mass of the potatoes from the start of the experiment to the end of the experiment will be larger. Additionally, the potato pieces left in a saltwater solution will decrease in mass, whereas the pieces left in water will increase in mass.

However, after refluxing for a while, yellow precipitates begin to form near the top of the flask. It was assumed that the remaining starting material was concentrated from a decrease volume to reappeared in solution. Nevertheless, this may have been a sign of contamination that will negatively affect the entire reaction. This observation later resulted in a yellowish

I predicted that the control would have a higher alcohol content than the experimental since beta and alpha amylase are working together. Since only Alpha-Amylase worked in the experimental, there was probably bigger carbohydrates present in the flask, therefore, there was a lower alcohol percentage since yeast can’t digest bigger sugars. b. My results also matched my prediction regarding mean reducing carbohydrate levels during the mashing process between the control and the experimental. My prediction stated that there would be less reducing carbohydrate ends in the experimental, which was proven in the data table.

The effects of alcohols on membrane have also been researched quite extensively. Previous studies have found that alcohols disrupt the structure of cell membranes (Goldstein, 1986). They have also found that ethanol has a stronger effect than other alcohols (Patra et al, 2005). From this research and literature the expected results of the experiment were to see an increase in membrane permeability, this result was observed. The study provides a brief insight into what kind of effects alcohol can have on cell membranes but it is limited.

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.

Yeast is alive because it can to metabolize and respond to environmental changes. The purpose of the first experiment was to determine whether yeast can metabolize. The bromothymol blue solution with yeast changed from blue to yellow. Bromothymol blue is an acid-base indicator that turns yellow in the presence of acid. The color change indicates that carbonic acid was formed from the reaction of water and carbon dioxide, a byproduct of metabolization.

The 3 concentrations of enzymes were 0.5 ml, 1.0 ml, and 2.0 ml of turnip extract, while the substrate consisted of 0.1ml, 0.2 ml, and 0.4 ml of hydrogen peroxide. In a separate tube, the control was made up of turnip extract and guaiacol, known as the color reagent. This was recorded the absorbance every 20 seconds for 3 minutes.

The solution with the pigments was spotted 15 times on both region A and region B and then allowed to dry. When the plate was dry it was placed into the tank for at least 20

When carbohydrate is utilized, acids are formed which changes the colour of the medium from green to yellow