Cellular Rspiration

LABORATORY REPORT FOR BIO411 Experiment 5 : Cellular Respiration Experiment 6 : Photosynthesis Title: Cellular Respiration Objective: To observe and determine cellular respiration in yeast/onion cells. * Measure respiration rate using different substrates. * Measure respiration rate at different temperature. Introduction: In this laboratory experiment, we are given 3 task. The first one is respiration in yeast. Second is respiratory indicator and the third one is observing mitochondria in yeast/onion cell. The first experiment is about investigation of sugars yeast. We will determine which sugars yeast can be use for cell respiration.When the yeast undergoes anaerobic/aerobic respiration, they will give out carbon dioxide. After that it will reacts with water to forms a weak carbonic acid solution. We will use BTB to monitor this reaction. Further explanation will be discussed at the discussion. The second experiment is respiratory indicator. Same concept with the first experiment. W e will measure the respiration rate using different substrates based on the table provided. The third experiment is observing mitochondria in yeast/onion cells. We will be using the staining technique in order to obtain the result of the experiment. * Task 1: Respiration in Yeast Materials: Beakers * Pipettes * Cuvettes * 20% Glucose * 20% Lactose * 20% Sucrose * 20% Maltose * Distilled water * Brom Thymol Blue (BTB) * Spectrophotometer * Measuring cylinders. Procedures: 1. The spectrometer is set to 565nm. Distilled water is used to set the reading to the pure level. 2. 8mL of 20% glucose is placed in the beaker using a measuring cylinder. 3. 1ml of Brom Thymol Blue (BTB) is added into a respective tubes using a pipette. 4. 4ml from the mixture of Glucose and BTB taken and placed in test tube then added with 0. 1ml of yeast extract. 5. The mixture then transferred into cuvette and placed into spectrophotometer. 6.The absorbance measured for 5 minutes. The reading taken within 30 se conds. 7. Steps 1-6 is repeated using 20% Lactose, 20% Sucrose, and 20% Maltose. 8. Reading obtained is recorded and compared with the others. Results: Time (s)| 20% Glucose| 20% Sucrose| 20% Maltose| 20% Lactose| 30| 1. 053| 1. 162| 1. 323| 1. 130| 60| 1. 051| 1. 161| 1. 310| 1. 123| 90| 1. 049| 1. 159| 1. 304| 1. 119| 120| 1. 048| 1. 159| 1. 297| 1. 116| 150| 1. 045| 1. 158| 1. 295| 1. 114| 180| 1. 044| 1. 155| 1. 292| 1. 111| 210| 1. 041| 1. 155| 1. 289| 1. 109| 240| 1. 040| 1. 154| 1. 287| 1. 107| 270| 1. 037| 1. 154| 1. 287| 1. 105| 300| 1. 035| 1. 154| 1. 284| 1. 103| Task 2: Respiratory Indicator Materials: * Test tubes * Yeast extract * 20% Glucose * Water bath * Parafilm * Distilled water * Tap water * Methylene blue Procedures: 1. 4 test tubes is obtained. 2. Each tube filled as table shown below, Tube 1 (room temperature)| Tube 2 (100? c)| Tube 3| Tube 4| 5ml yeast+1ml glucose+2ml methylene blue+2ml distilled water| 5ml yeast+1ml glucose+2ml methylene blue+2ml distilled w ater| 5ml water+1ml glucose+2ml methylene blue+2ml distilled water| 5ml yeast+1ml water+1ml methylene blue +2ml distilled water| 3. For tube 2, yeast is added and glucose is immersed the tube in water bath(100%) for 5 minutes.The, methylene blue is added. 4. Parafilm is used to cover all the tubes. 5. Initial time and color is recorded. 6. Time taken for the decolorisation to occur is recorded. Result: | Tube 1| Tube 2| Tube 3| Tube 4| Observation| Dark blue(no change)| Dark blue(no change)| Dark blue(no change)| Dark blue(no change)| * Task 3: Observing Mitochondrian of Onion Cells Materials: * Glass slides * Sucrose solution * Methylene blue * Toothpick * Onion cell * Cover slip * Microscope Procedures: 1. Clean slide is obtained and a drop of sucrose solution is placed on the center.Two drops of methylene blue added and mixed well by using toothpick. 2. Yeast is placed on the mixture of sucrose and methylene blue and cobered by the cover slip. 3. The slide immediately viewed unde r microscope. Results: 35 minutes is taken for yeast cells to decolorized, where blue stain turns clear. Disccusion: In our experiment, in order to achieved our objective which are to observe and determine cellular repiration in yeast/onion cells, we have to measured respiration rate using different substrates and we also have to measure respiration rates at different temperatures in Task 1, Task 2, Task 3.In Task 1: Respiration in yeast, the result we obtained shows that the 20% Glucose give the lowest value of absorbance compared to the others and 20% Maltose gave the highest value of absorbance. The order of absorbance is 20% Glucose