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Applied Science

Extracts from this document...

Introduction

APPLIED SCIENCE ASSIGNMENT 2 TASK 1(A) Experiment on diffusion Aim: to determine diffusion (in ordinary tap water). Apparatus: beaker, potassium permanganate and tin foil. Method: I filled the beaker (half) with ordinary tap water and I released the potassium permanganate into it from the thin foil. Results: within a matter of a few seconds to one and half minutes, the whole water turned purple beginning from the area where the potassium permanganate was dropped. Conclusion: this experiment showed the movement of potassium permanganate molecule all around the beaker of ordinary tap water thereby, concluding the fact that molecules would move from a place of higher concentration to a place of lower concentration (diffusion) passively. Experiment on osmosis The aim of this experiment is to determine osmosis. Apparatus: test tube, potato tuber, electronic balance, watch glass, different concentrated solutions of sucrose: 0.003m, 0.006m, 0.125m, 0.25m, 0.5m, 1m and water. Method: I cut the potato in six equal parts and I weighed them using the electronic scale. I then put each piece in different solution and I left them for 24 hours and I weighed them again. Result: Concentration of solution Original weight Weight after 24 hours water 11g 12.62g 0.003m 11g 12.21g 0.006m 11g 12.35g 0.125m 11g 11.91g 0.25m 11g 11.64g 0.5m 11g 10.36g 1.0m 11g 8.49g The result shows that osmosis actually took place in the experiment. As the concentration increased, the percentage of the weight difference decreased Conclusion: The experiment shows that the potato cells increase in mass in solutions with a high water concentration and decrease in mass in solutions with a low water concentration. This experiment helped me find out that osmosis occurs between two liquid substances with a partially impermeable membrane, and that the higher the water concentration is the larger increase in grams (mass). This means that the percentage will also be higher, increasing with the grams. TASK1 B Homeostasis means keeping a constant environment around the cells of the body. ...read more.

Middle

Conversely, if red blood cells are exposed to 0.9% sodium chloride, the cell will remain unchanged because this solution is isotonic to human cells. Also a 5% solution of glucose is isotonic to human cells. The lower percentage is needed with sodium chloride to produce an isotonic solution, in part because sodium chloride ionizes in solution more completely and produces more solute particles than does glucose. The concentration of water and solutes in the plasma is maintained within a very narrow range because if the plasma water concentration rises, the plasma becomes more dilute then the intracellular fluid within the red blood cell, then water will move down its concentration gradient across the membrane and into the red blood cell. This may cause the red blood cells to swell and bust. In this situation, the plasma is said to be hypotonic. On the other hand, if the plasma water concentration falls so that the plasma becomes more concentration than the intracellular fluid within the red blood cells, the plasma becomes hypertonic. Water passively moves by osmosis from the blood cells into the plasma and shrinking of the cells occur. One of the main functions of blood in human is to maintain an isotonic internal environment. This removes the problems associated with water loss or excess water gain in or out of cells. Paramecium and other single called freshwater organisms have difficulty since they are usually hypertonic relative to their outside environment. Therefore water will tend to flow across the cell membrane, swelling the cell and eventually busting it. This is not good for any cell. The contractile vacuole is the paramecium is response to this problem. The pumping of water out of the cell by this method requires energy since the water is moving against the concentration gradient. Task 3 Chemical reaction Chemical reaction is change in which one or more chemical elements or compounds react to form new compounds. ...read more.

Conclusion

Looking at the table, we can see that alveolar air is higher in oxygen than deoxygenated blood so diffusion will take place. Oxygen will diffuse from the alveolar into the deoxygenated blood and carbon dioxide will diffuse from the deoxygenated blood into the Alveolar air as partial pressure of carbon dioxide in the deoxygenated blood is higher than in the alveoli. At (1o.ooo) The table shows that oxygen will diffuse from alveoli into the deoxygenated blood and into the alveolar air. This is possible because the partial pressure of carbon dioxide in the deoxygenated blood is higher than that of the partial pressure of carbon dioxide in the alveolar air. Consequence For every 5000m increase in height, air pressure will be halved according to the task. At ground level, the partial pressure oxygen and carbon dioxide in the air we breathe will be normal. But as we begin to go up to 5ooom, we feel breathless and we will be more breathless if go up to 10.000m. In this case diffusion tends to be slower. The calculation of concentration gradient of O2 and Co2 at ground level. The partial pressure of oxygenated blood and extracellular fluid concentration gradient is O2: 14 .00-5.33=8.67kpa and C02: 6.00-5.33=0.67kpa. At 5000m O2 C02 Alveolar air: 7 take away from deoxygenated blood: 2.67. Deoxygenated blood: 3.00 take a way from alveolar air: 2.67. So 7 - 2.67 =4.33kpa. So 3.00 -2.67 = 0.33kpa. At 1000m O2 C02 Alveolar air: 3.5 take away from deoxygenated blood:1.34. Deoxygenated blood: 1.5 take away from alveolar air: 1.34. So 3.5 -1.34 =2.16kpa. So 1.5 - 1.34 =0.16kpa. Looking at the figures, concentration gradient reduces as one goes up. Therefore the rate of diffusion will decrease considerable as one goes up and this will affect one's ability in producing energy since the rate of diffusion of O2 is going to be slowed down and if you go higher than 10.000m you will run out of oxygen and eventually you will collapsed. ...read more.

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