Investigation Into the Effect of Temperature On the Rate of Respiration of Yeast Preliminary Work For my preliminary work, I am working with 35ml of yeast. I think that this is the best volume to use as it is about ¾ of a test tube full, and it allows for the yeasts expansion when heated. I am trying to find out the best range of temperatures to be used in finding out the respiration of the yeast, and I am also trying to find an equilibration time that can be used in the main experiment, as the time taken for the yeast to heat up to the desired temperature. Apparatus - One beaker - Two test tubes - Delivery tube with bung - Yeast (35ml) - Water - Stopwatch - Thermometer - 35ml syringe Method 1. A beaker was filled with water then heated to the desired temperature. 2. A test tube was then filled with 35ml of yeast and placed in the beaker of water. 3. The time taken for the yeast to heat up to the temperature of the water in the beaker was then measured using a stopwatch and thermometer. 4. A delivery tube with a bung was then placed into the test tube of yeast, with the bung end of the tube going into the test tube of yeast. 5. A second test tube was then filled with water and placed in a test tube rack. 6. The other end of the delivery tube was then placed into this second test tube. 7. The number of bubbles coming out of the delivery tube into the second tube per minute was then measured. Results – Equilibration time to be used = 4 minutes Temperature (oC) No. of Bubbles per min Equilibration Times 30 55 2 mins 3 secs 40 43 2 mins 36 secs 50
5. Two or more samples may be applied to each plate if they are kept
We then took 1ml of the 0.1% solution from test tube 2 using the glucose pipette and added it to test tube 3, we then used the H2O pipette and added 9ml of H2O into test tube 3 creating 10ml of 0.01% solution.
The procedure of the lab on day one was to get a ring stand and clamp, then put the substance in the test tube. Then put the test tube in the clamp and then get a Bunsen burner. After that put the Bunsen burner underneath the test tube to heat it. The procedure of the lab for day two was almost exactly the same, except the substances that were used were different. The
Equipment list: Test tubes were used to hold the milk, the lipase and the milk and lipase solutions. Test tube racks were used to hold the test tubes
The Effect of Temperature on the Rate of Respiration in Yeast There are two types of respiration in yeast: Aerobic: [IMAGE] Anaerobic: Glucose [IMAGE] Carbon dioxide + ethanol + energy Respiration is controlled by enzymes, which are proteins which speed up one or more biological reactions. Within any cell many chemical reactions are going on at any one time. Yeast has many different types of enzymes that speed up respiration. Prediction I predict that as temperature increases, the rate will also increase, until a certain optimum temperature, after which, the rate will decrease until the rate is zero as respiration has stopped completely. Reason
Test tube A will have a piece of potato which is this size. Test tube
The temperature of the reaction, as some of the energy produced converts into heat energy. At really high temperatures the reaction will stop because the heat will have denatured the enzymes.
* In the first dialysis tube (bag A), we would insert ten mL of one
Put a label on each test tube. With a pencil, number each test tube from one to twelve.
3.) Divide your 30g of white substance into the 4 test tubes evenly. You should put 7.5g into each test tube along with the water.
- Temperature was measured after and exact time i.e. 1 minute, 2 minutes, 3 minutes.
The pH of the solution would alter the rate of the reaction if it was
4. Put each group of potato discs in one of the 6 test tubes and watch
There were five test solutions used in this experiment, water being the control, which were mixed with a yeast solution to cause fermentation. A 1ml pipetman was used to measure 1 ml of each of the test solutions and placed them in separated test tubes. The 1 ml pipetman was then used to take 1ml of the yeast solution, and placed 1ml of yeast into the five test tubes all containing 1 ml of the test solutions. A 1ml graduated pipette was placed separately in each of the test tubes and extracted 1ml of the solutions into it. Once the mixture was in the pipette, someone from the group placed a piece of parafilm securely on the open end of the pipette and upon completion removed the top part of the graduated pipette.
tube. Add 6 mL of 0.1M HCl to the first test tube, then 0.1M KMnO4 and