# Cellular Respiration (Experimental Design) - Essay Example

Research Question Investigate the effect of temperature on the rate of respiration of various parts of plants (germinating seeds and dormant (non-germinating) seeds), by measuring the oxygen consumption and change In gas volume of restlessness containing either germinating or non-germinating seeds at different temperatures to measure the rate of respiration of these beans at different temperatures. Hypothesis 1 . Germinating seeds have a higher rate of respiration as compared to non- germinating seeds and the glass beads. 2.

As temperature Increase, rate of respiration increase, greater increase in volume of roisterers. Materials 2 thermometers 120 germinating seeds 120 non-germinating seeds 120 glass beads the size of germinating seeds Absorbent and non-absorbent cotton 6 washers 6 calibrated ml pipettes A bath of ice water A bath of water at room temperature Masking tape A bath of hot water Stopwatch 6 glass tubes with screw on lids, an external diameter of mm and a height of mm, the lids with a hole in the center, covered with a rubber seal through which pipettes can be inserted Variables

Independent Variables: Incubation temperature Type of seed used (germinating or non-germinating) Dependent Variables: Rate of respiration Constants: Time allowed for beans to respire Volume of KOCH added to absorbent cotton Type of glass tube used Volume of contents in each tube- the purpose of adding the beads along with the non-germinating seeds is to ensure that each restrooms Is uniform In volume. Controls: Respirator with only beads in it because it does not undergo any respiration Approach Two sets of three roisterers will be assembled during this lab exercise.

Each set 019 ruminated seeds, one will contain a mix of non-germinating seeds and glass beads, and a third will contain only glass beads. In each set of experiment, the rate of cellular respiration will be measured by measuring the oxygen gas consumption by using a respirator in water. This experiment measures the consumption of oxygen by germinating and non- germinating at room temperature and at ice water temperature. During cellular respiration, oxygen and carbon dioxide are simultaneously changing in volume.

Oxygen gas is being consumed by the respiring cells and carbon dioxide gas is diffusing out of the cells. The respirator, therefore, has to be able to deal with two simultaneously changing gas volumes. Introducing KOCH, which absorbs carbon dioxide, following this equation (CA + KOOK -?+ CHECK + H2O), converts the gas into Potassium carbonate (CHECK), a solid precipitate, therefore no longer governed by gas laws. This allows the respirator to measure only one variable, the consumption of oxygen gas by living cells.

The change in the volume of gas in the respirator will be directly proportional to the amount of oxygen consumed. The respirator with glass beads alone will not show any changes in volume due to atmospheric pressure changes or temperature changes. As oxygen is used up by the respiring seeds, the gas pressure inside the respirator will decrease and the water will flow into the pipette down its pressure gradient (a region of higher pressure to a region of lower pressure) Experimental Procedure I. Making a respirator 1 . Count 30 germinating seeds and place them into a measuring cylinder.

Add ml of water and record down the volume of the seeds and the water. The recorded volume has to be constant with the other 2 tubes. Filter the contents and discard the filtrate. The reiterate will be transferred into a glass tube labeled “Tube la” later 2. Count 30 dormant seeds and place them into a measuring cylinder. Add 30 ml of water. Add in glass beads slowly until the volume reads the same as the recorded volume measured in tube 1 . This is to ensure that the contents of each cylinder has the same volume. Filter the contents and discard the filtrate.

The reiterate will be transferred into a glass tube labeled “Tube AAA” later on. 3. Add ml of water into a measuring cylinder. Add glass beads until the volume reads the same as the recorded volume measure in tube 1 . Filter the contents and discard the filtrate. The reiterate will be transferred into a glass tube labeled “Tube AAA” later on. 4. Add a piece of non-absorbent cotton onto each tube and pack the cotton towards proper protective gear, into each tube. Ensure that the cotton is packed at the bottom of each tube using a glass rod. 5.

Add a piece of non-absorbent cotton onto each tube and pack the cotton towards the bottom of the tube as well. The non-absorbent cotton functions as a separator to separate the seeds from the KOCH as the KOCH is caustic and can cause contamination f the seeds, affecting the germination of the germinating seeds. 6. Transfer the reiterate from previous into each tube respectively. 7. Screw on the lids onto the tubes and insert a ml pipette through the center hole and prevent leaking of air with a rubber seal. 8. Make 2 more of each tubes and label them b, LLC, b, c, b, c respectively. I. Setup of experiment 1 . Set up three different water baths with differing temperatures: a. Room temperature (25 degrees Celsius) b. Cold (10 degrees Celsius) c. Warm (40 degrees Celsius) 2. Now submerge the roisterers (1 a, AAA, AAA) on their sides into the room enrapture water bath and let them sit for 7 minutes so their temperature becomes equal to the water bath temperature. Ensure that the roisterers are tilted at the same angle by laying them on a line of masking tape across the breadth of the bath.