THE EFFECT OF GLUCOSE CONCENTRATION ON ANAEROBIC RESPIRATION IN YEAST
INTRODUCTION:
Yeast, also known as a saccharomyces cerevisiae, is single celled eukaryotic cells that are in the kingdom fungi and are unicellular organisms which normally reproduce asexually by budding at a very high rate. Scientists quite often decide to work with yeast because of its features fast growing rate and the fact that yeast 's DNA can be easily manipulated. Some types of yeast can be found naturally on plant or in the soil. Also it is worthwhile mentioning that yeast feeds on sugar very well, and so that I decided to use glucose.
My independent variable will be the concentration of glucose solution. To make sure that that my test will be fair, I will make
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Temperature
Measured by a thermometer
C: Varies throughout the day, but each yeast solutions gets the same temperature
It is important to keep the temperature the same throughout the whole experiment because enzymes might work faster or slower depending on the temperature.
DEPENDENT VARIABLE:
Burette
Placing portions of different concentration of yeast solution separately in the apparatus
Count the amount of bubbles every 1 minute
To read the burette correctly it is important to remember that the lowest numbers start on top and go up to the highest numbers at the bottom.
The curved surface at the top of the liquid level is called a MENISCUS.
METHOD:
Weigh four different amounts of glucose 1g,2g,3g,4g and 5g and place each amount into a conical flask .
Add 100 ml of water to the conical flask and swirl until the glucose is fully dissolved.
Yeast has to be heated up before mixing it with
of sugar to 25ml of water and dissolve it. When we have the water at
Step 4: Place the test tubes into separate coffee cups to maintain the upward position. Add 2 mls of the catalase solution to each of the test tubes and then place tubes1, 2, and 3 in the conditions described above. For test tube 4, fill the coffee mug half full of boiling
In the experiment we used Turnip, Hydrogen Peroxide, Distilled Water, and Guaiacol as my substances. On the first activity, Effect of Enzyme concentration of Reaction Rate for low enzyme concentration, we tested three concentrations of the turnip extract, and hydrogen peroxide. For the Turnip Extract I used 0.5 ml, 1.0 ml, and 2.0 ml. For hydrogen peroxide we used 0.1 ml, 0.2 ml, and 0.4 ml. We used a control to see the standard, and used a control for each enzyme concentration used. The control contains turnip extract and the color reagent, Guaiacol. We prepared my substrate tubes separately from the enzyme tubes. My substrate tube
The objective of the experiment is to test the effect of five different temperatures on the rate of carbon dioxide production in yeast. In order to achieve this, five fermentation tubes are filled with 30 ml of yeast and a sugar culture. The tubes are then added to water baths of varying temperatures to determine which one yields the most carbon dioxide. Results support the conclusion that yeast will produce carbon dioxide most efficiently in a setting with a temperature at or about 45°C.
Most enzymes work best at body temperature, higher temps will cause the enzyme to no longer work properly
Saccharomyces cerevisiae, also known as baker’s yeast, is eukaryotic fungi (Nakasono, 2003). When yeast is fed, it uses oxygen and a sugar source to produce energy (ATP), and CO₂, the way humans do (Nakasono, 2003). Yeast undergoes aerobic respiration which involves oxygen.
There are many procedures during this lab and many materials needed for an accurate analysis of data. First, fill a 100 mL graduated cylinder with 50 mL of water. Add 25 germinating peas and determine the amount of water that is displaced. Record this volume of the 25 germinating peas, then remove the peas and put those peas on a paper towel. They will be used for the first respirometer. Next, refill the graduated cylinder with 50 mL of water and add 25 non-germinating peas to it. Add glass beads to the graduated cylinder until the volume is the same to that of germinating peas. Remove the beads and peas and put on a paper towel. They will be used in respirometer 2. Now, the graduated cylinder was filled once again, determine how many glass beads will be require to reach the same volume of the germinating peas. Remove the beads and they will be used in respirometer 3. Then repeat the procedures used above to prepare a second set of germinating peas, dry peas and beads, and beads to be used in respirometers 4,5,and 6, the only difference is the temperature of the water.
The correct syringe is used to place 10 cm3 of the first glucose solution into the boiling tube.
There were several steps completed to prepare for the experiment. Three dialysis tubes were filled with approximately the same volume of distilled water and then were tied shut. The initial mass (in grams) of the tubes was taken using a triple beam scale. I then filled three 500 mL beakers with 400 mL of water each and dissolved different masses of solute (table sugar) in each beaker in order to make 5%, 10%, and 20% solutions. The beakers were labeled accordingly, and then 20 g, 40 g, and 80 g (respectively) of table sugar was weighed out using a digital scale and placed into the corresponding beakers. The sugar was stirred in using a stirring rod until all of the solute was completely dissolved.
3.Measure and add 0.5g, 1.0g, and 1.5g of sucrose into 3 of the test tubes. Do not add sucrose into the 4th test tube because this will be the control. Lightly shake the test tube to mix the contents together.
The CO2 production was measured with a CO2 meter (+/- 1ppm), in order to determine the rate of anaerobic cell respiration in yeast.
For the experiment, the changes of temperature on anaerobic fermentation the process in which cells undergo respiration without oxygen in Saccharomyces cerevisiae was observed. The purpose of this experiment was to test the effect of four different temperatures on the rate of carbon dioxide production in yeast by measuring the fermentation rate. Saccharomyces cereviviae, also known as Baker 's yeast, is a unicellular, eukaryotic sac fungus and is good for this experiment because of its characteristic of alcohol fermentation. It was hypothesized that fermentation increases with increased temperature to a point of 37°C; above that point, enzyme denaturing will occur and fermentation will decrease. The group was able to document the carbon dioxide production and mark each of the temperature intervals which were tested at temperatures 4°C (refrigerator temperature), 23°C (Room temperature), 37°C (Human body temperature) and 65° Celsius (Equal to 150°F). The experiment was conducted by pouring yeast solution with 2% glucose in fermentation tubes, placing the tubes in the appropriate incubation temperature, marking the rise of the gas bubbles in the fermentation tubes which indicated carbon dioxide production. The results of this experiment were not supported by the hypothesis, creating different results from what was predicted. It is important to understand the fermentation rate of yeast so
2. Add about 20 mL of distilled water and stir the mixture with a glass stirring rod to dissolve the sample. There may be a small amount of insoluble residue. If your sample does not dissolve completely, remove the insoluble material by filtration.
Fermentation is the chemical process that breakdown sugar by microorganisms to get energy and produced waste without the help of oxygen. Metabolism is the chemical reactions that specific substrates bind to enzyme that break them down. Yeast fermentation is the alcoholic fermentation types that involved in the chemical reaction metabolic stage of glycolysis to oxidize the glucose into two pyruvate molecules; and the overall net energy yield were two ATP molecules, and two NADH molecules (textbook page 170). In pathway of anaerobic (without oxygen), Yeast can metabolize the sugar to release energy adenosine triphosphate, and produce the waste carbon dioxide and ethanol (textbook 180).
Fermentation a metabolic process with occurs in the absence of oxygen molecules also known as an anabolic reaction. It is a process of glycolysis in which sugar molecules are used to create ATP. Fermentation has many forms the two most known examples are lactic acid and alcoholic fermentation (Cressy). Lactic acid fermentation is used in many ranges from food production such as bacteria to its use by fatigued muscles in complex organisms (Cressy). When experimenting with organisms such as yeast which was done in this experiment you follow the metabolic pathway of Alcoholic fermentation (Sadava). Where the sugar molecules are broken down and become ethanol (Sadava). But the end product of fermentation is the production of