Biology Lab Report
Investigating Alcoholic Fermentation and the Affects of Yeast on Dough
Aim: The aim was simply to investigate whether or not yeast had any affect on causing dough to rise when baked and to experiment with alcoholic fermentation eg. to see if it gave off carbon dioxide.
Introduction: Following a few weeks of fermentation theory, groups of three to four were assigned and told to conduct a series of experiments involving the affects of fermentation. My group consisted of myself, Won Jin, Brendan and Sun-Ho and we chose to investigate alcoholic fermentation and the affects of yeast on dough, more specifically to see if yeast caused the dough to rise in anyway. We followed the instructions in our biology textbook on
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Through the Test Tube, we hoped that the Carbon Dioxide given off would travel through the tube and turn the Lime Water (used as an indicator) into a milky colour. Without much surprise it did and we could conclude that the Yeast did give off Carbon Dioxide, much like our previous experiment (Carbon Dioxide given off by the Yeast causing the Dough to rise).
Conclusion: From our results I can safely assume that my Hypothesis was correct for both experiments and I can now, for sure, say that Yeast does cause Dough to rise. Other than stating that obvious fact, not much can be said for the first experiment other than we proved Yeast is extremely important for making the Dough rise. Without the Yeast giving off Carbon Dioxide, the Dough wouldn't rise. It would also be good to note that the Dough's sticky material traps the Carbon Dioxide, causing the mound to rise.
For our Alcoholic Fermentation experiment, once again, my Hypothesis was right on the mark. The Fermentation caused by the Yeast created heat, warming up the tube. Also it turns the sugar into Alcohol and simply smelling the Test Tube, after the experiment, can also prove this as Alcohol has a very distinctive smell, easily recognised. My third observation of this experiment showed that Carbon Dioxide was given off, turning the Lime Water milky.
I cannot say I
There are many substances that can be manipulated and cause the rate of reaction in fermentation to either speed up or slow down. Substances that alter the rate of the reaction could be temperature of the water, the yeast concentration, pH, and the glucose concentration. In the experimental group of the experiment the amount of yeast concentration was manipulated. The objective of this experiment was to determine what factors affect the rate of the fermentation. To test this objective we changed the amount of yeast being used. A higher yeast concentration replaced the controlled yeast amount. A prediction made by my group was that higher amount of yeast would speed up the process of fermentation. Our null hypothesis is there will be no
Fermentation is a metabolic pathway that produce ATP molecules under anaerobic conditions (only undergoes glycolysis), NAD+ is used directly in glycolysis to form ATP molecules, which is not as efficient as cellular respiration because only 2ATP molecules are formed during the glycolysis. One type of fermentation is alcohol fermentation, it produces pyruvate molecules made by glycolysis and the yeast will break it down to give off carbon dioxide, the reactant is glucose and the byproducts are ethanol and carbon dioxide. In this lab, the purpose is to measure whether the changes of
PH can affect the way fermentation occurs due to the irregularity of the acidity or alkalinity within the glucose solution. This is an enzyme-based reaction that is susceptible to pH. The aim of this experiment was to determine how pH affects the yeast fermentation rate by performing the experiment numerous times with a different pH of glucose solution which included pH 3, 5, 7, 9, 11. The hypothesis was ‘If the pH is lower than the neutral point then the fermentation reaction will occur faster?’ The experiment conducted was to measure the amount of C02 produced by the yeast going into fermentation, however varying the pH of glucose solution by using different pHs . To test this every 5 minutes the volume of gas in the test tube was observed and recorded until a period of 30 minutes had been. The end results
Abstract: This lab’s purpose was to see how different levels of yeast, distilled water, and sugar interact to affect the level of carbon dioxide evolved in fermentation. In this experiment we had two sections. The first section tested four test tubes with varying levels of yeast, glucose and distilled water for evolved carbon dioxide levels. The tubes were timed for 20 minutes. The amounts of solution in the test tubes are noted in the methods section of this lab report. The second section of the lab used three test tubes and flowed the same procedure except added spices. The levels of ingredients are also in the methods section. The main goal of this experiment was to see the effects of yeast concentration.
There are many processes that are needed to occur to produce something that help organisms live. Cellular respiration and fermentation are two process that are important to the survival of organisms. Cellular respiration is the way cells make ATP, which they need to survive. The process starts with the breaking down of glucose into other compounds that can be used by the cell. However, there are more steps in the process than just cellular respiration and how precise cellular respiration is depends on how much ATP can be taken from food particles in the body (Hill 646). Fermentation is mostly known in the world of beer and wine, but it also produces lactate in organisms. Fermentation is breaking glucose into separate components like water or carbon dioxide, much like that of cellular respiration. N’guessan and some peers did an experiment and they found that after fermentation had stopped, they had over 200 counts of yeast in the beer (N’guess, Brou, Casaregola, Dje 858). Under the
The experiment answered the question; How do yeast metabolize different fuels? My hypothesis was that yeast could metabolize some fuels and not others, but all the fuels would be metabolized at a different rate. My prediction was that yeast could metabolize all the fuels we used, but it would metabolize at different rates. Yeast metabolizes different fuels by fermentation without the presence of oxygen; this is the method we used in the lab. The control group produces carbon dioxide because there are still different sugars in the water. These sugars are there because we used normal tap water, which contains many different molecules and ions inside the solution. It is important to have the control group to compare to the other fuels because we can see how much the other fuels have created compared to the normal water from the
In the first part of the experiment, the goal is to observe the metabolic and fermentation rates of yeast. The class worked together to determine the specific measurements of gas that was produced over time using the fermentation tubes. During the second portion of this lab, Cellular Respiration was observed in a redox reaction converting succinate into fumarate. Di-chlorophenol, also known as DPIP was used to represent an electron acceptor that collects the Hydrogen ions released by the redox reaction. This redox reaction is what is used for The Citric Acid Cycle to continue the aerobic respiration cycle.
The procedure for this experiment was to first obtain four balloons and blow them up in order to stretch them. Then obtain and fill the four large test tubes each with thirty milliliters of warm forty degrees Celsius water and two grams of dry yeast which was weighed on a scale and scooped out by a spatula. After five milliliters of water, ten percent glucose, fructose or sucrose went into one of the four test tubes. Then parafilm was placed on top of each of the test tubes to seal them and they were swirled activating the yeast through rehydration. After swirling the film was removed and the balloons were tightly placed on the test tubes. Then finally observed the tubes build up of CO2 all the while swirling gently every fifteen minutes, recording observations.
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
Hypothesis: If the mass of yeast (g) is increased the rate of fermentation of glucose (mL/s) will increase.
Alcoholic fermentation is a type of fermentation that only occurs in bacteria or fungi, when oxygen isn’t available. It starts off by taking in glucose, and through glycolysis, breaks it down into 2 Pyruvic acids. Later, it turns the pyruvic acid and NADH into 2 Ethyl alcohol, 2NAD+, and 2CO2. Yeast is a type of fungus that is in bread and helps undergo alcoholic fermentation to make the bread rise. In order to function and perform alcoholic fermentation, yeast
We conducted this experiment in order to observe the rate of respiration in yeast cells. When yeast cells metabolize glucose, they produce carbon dioxide and that can change the color of water. This connects to the purpose of this lab because respiration produces CO2 which is acidic and lowers the solution’s pH. Rate of respiration cannot be measured directly; however, it produces CO2 which is acidic and will lower the pH of a solution, meaning that if the solution's pH drops sufficiently, the color (huge indicator) would change. In this scenario, phenolphthalein, which changes color from pink to colorless at pH 8.2, was used. The time taken for decolorization corresponds to rate of CO2 production which is inversely proportionate to rate of respiration (shorter time = greater rate).
[online] Available at: https://coopers.com.au/our-beer [Accessed 8 Apr. 2017]. Lodolo, E., Kock, J., Axcell, B. and Brooks, M. (2008). The yeastSaccharomyces cerevisiaeâ the main character in beer brewing. FEMS Yeast Research, [online] 8(7), pp.1018-1036.
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
drop one of them and it was to shatter, you must not pick it up