Higher Concentration of Sucrose Lowers the Mass of a Potato Independent Variable: Concentration of Sucrose used Dependent Variable: Mass of each Potato after Experiment Constant: Size of Potato being used at room temperature Introduction We learned about hypertonic and hypotonic environments before this lab as well as what takes place during osmosis. Do potatoes loose or gain mass when soaked in specific solutions such as sugar or salts? Sugar is a large molecule and has low permeability. Potatoes are a starch which means it is composed of many polysaccharides, therefor has low permeability. Salts are also molecules with low permeability.
Which is why I believe I found that most of the points on my graph were spread over a wide range. Also, the experiment required more than one piece of potato and each potato might have had more water in it or less thus affecting the mass of potato. My partner and I also had used different potatoes one can deduce that these potatoes were of different qualities. Not to mention, another factor which played a big role in affecting the outcome of my results was that the grape juice when placing it into the test tube might have not been distributed equally around the potato cylinder as I found it to be sticky and would take time to slide down when touching the test tube. So, each potato cylinders may have contained different amount of sugar thus affecting the rate of osmosis.
This indicates that all of the solutions have been hypertonic in relationship to the potato tubes. The concentration of the solute (salt or sugar) has been higher in them than the concentration of the solute in the solutions that we have tested them in. Nonetheless, some solutions have been a closer match to the osmolarity of the potato tubes than others, such as 0.6 (M per mL) which has caused the tissue to lose -3.6% of its weigh only, compared to 1.0 (M per mL), which has caused the potato to lose -36.6% of its weight. Therefore, the net movement of water in the solutions that displayed a bigger loss in the weight of potatoes has been higher than solutions where the potatoes have only lost a small amount of their weight. This indicates the bigger the weight loss in the mass of the potato, the bigger the difference between the two concentrations of the potato and the solution that it is soaked
The solution that have a molarity of 0, cause the object to be isotonic. If the temperature of the glucose solutions that had different molarities increased, the reaction of the potatoes weight would have happened faster. And vice versa, if the temperature of the glucose solutions that had different molarities decreased, then the reaction of the potatoes weight would have happened slower. If someone used animal cells instead of plant cells in this experiment, nothing would change because the only difference between plant cells and animal cells is the cytoplasm which has nothing to do with the experiment. A solution that is five percent glucose would be isotonic compared to red blood cells.
Type of tissue: the type of tissue has a certain effect on rate of osmosis since the amount of glucose in each type of tissue differs. This will be controlled by using only one type of tissue which is the same potato. Materials: 1 large potato piece 1 cork borer 1 scalpel 1 clear plastic ruler 4 small
Tissue Papers Absorb Less Liquid in Volume When Concentration of Salt Increases This study was done in an effort to find out the minimum number of papers needed to wipe up a spill so that anyone could prevent wasting paper. In this investigation, sheets of tissue papers were dipped into salt water with different concentrations and soaked until the water traveled to the top, then the amount of water a paper absorbed in terms of both the mass and the volume was recorded. The result showed a strong, positive linear relationship between mass absorbed and salt concentrations, while it showed a slight decrease in volume absorbed with increasing salt concentrations. Further researches could be done to change the substances or even mix different solvents
The effect of temperature on Membranes (Beetroot Lab) The aim of this lab was to determine the stress that various temperatures have on biological membranes. This was done through experimenting with beetroots and looking to see whether various temperatures affected the color in which beetroots changed/turned into. Raw Data Table 1: How various temperature of water affects the rate of light of absorbance Temperature of water (+/-0.5 °C) Absorbance value of beetroot in various temperatures (+/-0.005 Abs) Trial 1 Trial 2 Trial 3 Trial 4 Trial 5 5 0.155 0.111 0.122 0.153 0.136 30 0.232 0.191 0.124 0.189 0.212 45 0.144 0.283 0.133 0.152 0.287 60 0.291 0.241 0.245 0.278 0.265 75 0.426 0.309 0.333 0.478 0.384 Qualitative Data During the experiment I realized that as the temperature of water increased the color of the beetroot intensified. This is because the beetroot membranes are damaged, making the red pigment leak out into the surrounding environment. Whereas for lower temperatures I had realized the color of
is the results of the effect of enzyme concentration on the potato enzyme. The 100% enzyme concentration had the highest average rate of O2 production being 7.79ml/min. This is because when there is a 100% concentration there is more molecules of the catalase for the hydrogen peroxide to react with. As the concentration is being diluted, the concentration of the catalase is decreasing so the molecules are less likely to collide and react. When the enzyme is at a 0% concentration there should not be any 02 produced and this is where some errors may have occurred.
Desalination through reverse osmosis removes the salts from the water with the help of membrane. These membranes are non porous and allows certain materials to pass through them. The holes in the mesh of reverse osmosis membrane are of the size that allows only water molecules to pass through them, leaving behind the salt molecules. Salt is a prospective by-product of desalination by reverse osmosis. High operating pressure is required to push the water through these membranes.
Simultaneously, there was no significant difference in hardness. However, the cooking method did not affect the whiteness of instant rice. The volume expansion of BPC after rehydration in boiling water for 3 minutes is presented in Table 1. These results revealed that cooking method and drying with industrial microwave oven did not affect the volume expansion of rehydrated instant rice which is similar to the results of Prasert and Suwannaporn. From Table 1, it was found that the volume expansion of instant rice with the industrial microwave oven is less and this was consistent with Jiao et al., (2014), who found rapid drying resulted in less volume expansion.