Yeast Fermentation Lab

The experiment was conducted to determine the impact different yeast amounts had on yeast fermentation. It was hypothesized that the more yeast added the more CO2 would be produced. The carbon dioxide production was measured in the fermentation of yeast with solution of no yeast in test tube 1, 1mL yeast in test tube 2, and 3mL of yeast in test tube 3 over a period of twenty minutes. All of the yeast amounts produced CO2, but test tube 3 was the most efficient of the three.

Observations: During the experiment, bubbles were present from the water in the electric water baths that were set at temperatures of 50 degrees Celsius and 60 degrees Celsius. This is because the water has passed its boiling point and began to boil. The glucose powder had a white color. The yeast powder had a mild yellow color. When the glucose solution was mixed with water, it gave a clear color. When glucose solution was mixed with the yeast, it produced a murky yellow color. Bubbles also arose when CO2 was being lost in the experiment under each desired temperature.

    One possible source of error that can affect the results was that a mercury thermometer was used instead of an electronic one. The use of a mercury

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.

During this experiment, sugar sources were varied and respiration rate evaluated. To begin, a water bath was set at 30 degrees Celsius. This creates an optimum temperature for the enzymes in yeast to breakdown sugar and give off CO₂. Each sugar source, glucose, sucrose, lactose and glycerol were all added to its own unique yeast sample, one at a time. Each sugar source that was added to the yeast solution was immediately incubated for 10 min, then was transferred to a respiration chamber. The CO₂ sensor was put in, recording the CO₂ respiration for 4 min. This process was done for each sugar source. The reparation rate was recorded through Logger Pro. After 4 min passed, the slope was recorded, resulting in respiration rate.

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

2. Both the measurements of temperature and volume limit the precision of the data because for temperature, we could only round to the nearest tenth, which limits the amount of sig figs. In addition, because the total volume was only 50mL, there could have been another volume that would have exceeded the optimal ratio of this experiment.

Like why does yeast bubble, when was yeast discovered for baking purposes, and how do we use yeast in everyday life? Well, when you add a pinch of sugar to your yeast it will bubble, this is if it's not expired. The yeast feeds on the sugar and once the released carbon dioxide expires the dough will rise. Adding a pinch of sugar will be a constant in my project. Vinegar cancels out the ability for yeast to grow, so this is why many people use vinegar for a home remedy for yeast infections on the body. With only a small amount of baking soda yeast rises more, but if there is too much then the growth will get

off heat’(WIKIPEDIA 2015, Fermentation, https://en.m.wikipedia.org/wiki/Fermentation, accessed on the 12/8/2015).The chemical reaction for fermentation is C6H12O6 → 2 C2H5OH + 2 CO which is otherwise known as one glucose molecule converted into 2 ethanol molecules plus 2 carbon dioxide molecules. Fermentation usually occurs in the lack of oxygen and becomes the cells primary which can be know as the ATP production. The type of variables that can affect the rate of fermentation are: the type of yeast, some may attract bacteria better than others which is bad as it can change the flavour of the ginger beer also some yeasts can tolerate Ethanol better than others which can produce microorganisms which we don't want. It is stated that ‘when there’s

1. Lab reports are to be computer-generated and double-spaced. All sections of the report must

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.

In addition, yeast is also responsible for ethanoic fermentation to make one of my favorite beverages known as beer.

Sugars are vital to all living organisms. The eukaryotic fungi, yeast, have the ability to use some, but not all sugars as a food source by metabolizing sugar in two ways, aerobically, with the aid of oxygen, or anaerobically, without oxygen. The decomposition reaction that takes place when yeast breaks down the hydrocarbon molecules is called cell respiration. As the aerobic respiration breaks down glucose to form viable ATP, oxygen gas is consumed and carbon dioxide is produced. This lab focuses on studying the rate of cellular respiration of saccharomyces cerevisiae, baker’s yeast, in an aerobic environment with glucose, sucrose, lactose, artificial sweetener, and water as a negative control. A CO2

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