Test Tube With The Temperature example essay topic

Implementing: -1. First, I gathered the necessary equipment: SS Thermostatically controlled water baths I ceSS ThermometerS S Stop watch Test tubes Photographic film (b / w) SS SyringeS S Test tube rack RulerS S Scissors SS O. 1% trypsin made in pH 7 buffer solution Mounted needle 2. I then decided on the range of results and temperatures I was to investigate. I decided to observe 20 o, 30 o, 40 o, 50 o, 60 o, 70 o and 80 o.

3. Next, I label each test tube with the temperature to be investigated and then added 2.5 cm 3 of Trypsin solution. 4. I ensured that I cut the necessary pieces of film using a ruler and a pair of scissors.

I cut pieces that were 2 cm in length, and 1.6 cm in width each. 5. The only water baths of my choice that were running were at 30 o and 60 o. I therefore had to use the Bunsen burner etc. for the rest of the temperatures (excluding 20 o). I kept each test tube heated for 5 minutes. 6.

I added the photographic film pieces just before I placed the test tubes in the water baths / Bunsen burners, and ensured that they submerged fully before I began timing. 7. I carefully and frequently examined each test tube for the time that the film became transparent and listed the result Results: -Temperature (oC) 20 30 40 50 60 70 80 Time taken (minutes) 23: 38 16: 37 6: 06 6: 40 7: 53 8: 24 10: 15 Time taken (seconds) 1418 997 366 400 473 504 615 Rate of Reaction - (1/time in mind) 4. d. p 0.0426 0.0606 0.1667 0.1538 0.1250 0.1176 0.0976 It is evident from the graph and the table above, that as the temperature is increased, the amount of light passing through the tested solutions is decreased, and therefore the amount of pigment released from the beetroot samples is increased. The results produce a graph with negative correlation, a curve that has a negative gradient. The graph shows that as the temperature is increased, the colorimeter reading is decreased. The structure of my results proves my theory correct.

The increase in temperature breaks bonds in the (mainly intrinsic) proteins in the cell membranes of the beetroot cells. The a membrane that holds the pigment, when this is affected, the pigment escapes and is released into the cytoplasm. When the outer cell membrane is denatured, the pigment is transferred into the solution. The diagram above supports my theory.

The intrinsic proteins in the cell membrane are denatured at a certain temperature. This is where the gradient of the curve changes most sharply. On the line graph, this point is at approximately 65 oC, at temperatures below this point, the results are very close. This is because very little or no proteins would be denatured, meaning the very little pigment would have only be released through other certain gaps in the membranes. This explains the shape of my graph. Evaluation I believe my results were accurate, however I did not have enough time to reread off the colorimeter.

I do not believe there were any anomalies resident in my results, because the results fit my scientific theory. The apparatus I used in the experiment were suitable. However, there was one limitation to the precision of my results. This was the fact that not all the beetroot samples came from the same beetroot because they were 2.5 cm in length. The reason why this is a limitation is because one beetroot may have more pigment in its cell than another, cantering the results slightly. A very serous mistake I made has the amount of high colorimeter readings, yet decreased the effects of any limitation.

I also believe that using a Bunsen burner to heat the test tubes rather than a thermostatically controlled water bath consumed a lot of time. Overall, I believe the experiment was a success, and my results supported my theory, however they were slightly inaccurate and a little too high.