Lab Report - Cellular Respiration PDF

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Cellular respiration...

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FAKULTI SAINS GUNAAN UNIVERISITI TEKNOLOGI MARA CAWANGAN SARAWAK KAMPUS SAMARAHAN 2 BIO150 – METABOLISM & CELL DIVISION

SCIENTIFIC LAB REPORT NAME: RADIN NUR ATHIRAH BINTI RADIN SAIFUL AFFENDI STUDENT ID: 2019210004 GROUP: AS1202A EXPERIMENT TITLE: CELLULAR RESPIRATION LECTURER: ANG CHUNG HUAP DATE OF SUBMISSION: 30/05/2020 --------------------------------------------------------------------------------------------------------------------------Declaration of Academic Honesty Academic honesty or academic integrity is a very important virtue that all students should uphold at all times. I declare that the lab report submitted is not plagiarised and is entirely my own work, and that no part of it has been copied from any work produced by other person(s)/ source(s) or provided by any other student(s). I understand that issuing a false declaration can result in severe penalties and I am willing to be penalized if any form of copying found valid.

Introduction: Yeast are one of simple organisms that can adapt either aerobic or anaerobic respiration. In this experiment, we will study the activity of enzymes in which both use NAD+ as a cellular oxidizing agent. Methylene blue is used as an oxidizing agent in the experiment. As the result for reduction in the enzyme reaction, we will see that the blue color from methylene blue changes to colorless.

Objectives: 

Identify the type of cell respiration in the yeast.



Interpret the results of yeast reaction by using methylene blue as the artificial hydrogen acceptor.

Apparatus: Boiling tubes, thermometer, Bunsen burner, syringe, tongs, beaker, dropper Material: Half drop of methylene blue, 10mL of yeast

Procedure:

1. Two test tube labeled with A and B 2. Each tube filled with 10mL of yeast 3. Tube B boiled in a beaker for 5 minutes 4. Half drop of methylene blue added into each tube. The tube shakes vigorously and let the blue color to spread evenly 5. The color changes in all tubes were observed 6. The results were recorded into a table

Result: Table 1.0: Yeast reaction Treatment

Color observed

Color observed

Into boiling water 5

Test tube A (in the video) No

(Expected Result) Test tube B Yes

minutes Drops of methylene blue Few minutes incubation Vigorous shaking

Light blue Decolorized Light blue

Blue Does not decolorized Blue

Discussion:

For test tube A, the yeast solution undergoes respiration process, the methylene blue reaction will become decolorized to light blue. When the tube was shaking vigorously, the methylene blue will be oxidized and changes the color from light blue to blue. When it stopped, the removed yeast will undergo aerobic respiration, reduction process will occur and change the blue color to light blue. On the other hand, for test tube B, the boiling process will denature the enzyme in the yeast. The color of the solution remains unchanged. The yeast cells are dead due to the high temperature. Thus, it does not decolorize the solution after being heated. Methylene blue will be decolorized when the solution is being reduced, the NAD will substitute, and it will be reduced during respiration process. When the temperature of a yeast solution increases, the kinetic energy of the particles will increase, the particles will be collided with each other more often and it will increase the number of enzyme-substrate complexes formed. Furthermore, the amount of product produced per unit time will increase as the temperature increase the rate of respiration of yeast will increase. As the rate of respiration process increases, the amount of product produced per unit time by dehydrogenase enzymes in yeast will increase, so more amount of methylene blue can be reduced in at one time. Once the solution reaches optimum temperature, the time taken for methylene blue to change color from blue to colorless will be slower as that the amount of methylene blue reduced per unit time increases. After it reaches optimum temperature, the time taken for methylene blue to change to colorless and being reduced will become faster as the respiratory enzymes begin to denature resulting in a small amount of dehydrogenation at a time, this reaction will continued to occur until the yeast solution dies. In this experiment, we need to pay attention to the temperature and avoid parallax error. Next, wear appropriate clothing to avoid the methylene blue touch direct to our skin.

Conclusion:

Hypothesis is accepted, the methylene blue will change from light blue to colorless to show that the yeast solution undergoes respiration process. The yeast will undergo reduction respiration process to change the methylene blue color. During respiration process,

hydrogen

atoms

will

be

removed

from

glucose

molecules

by

dehydrogenases. In this experiment, methylene blue acts as an artificial hydrogen acceptor because when it is reduced it will become colorless. Reference: 

https://www.thestudentroom.co.uk/showthread.php?t=3221013



https://www.coursehero.com/file/p3q7hqg5/Analysis-Experiment-1-For-boilingtube-A-respiration-by-yeast-methylene-blue-is/



http://matriculation-biology.blogspot.com/2017/02/experiment-16-cellularrespiration.html...