Yeast Lab Report

Sucrose is a crystalline sugar having the formula C12 H22 O11, found in many plants, especially sugarcane, sugar beets, and sugar marbles (American Heritage: Student Science Dictionary 331). Sucrose is a type of sugar that is extracted from sugar cane, normally used for baking goods. It is like table sugar that is broken in pieces to become glucose. When carbohydrates and sucrose are broken down in food and will form glucose, the level in the

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

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.

were scrapped from the teeth and the second was an unknown given. It resulted that the unknown

From our data, the main interpretation that can be observed is that in Trial 3, where 2 mL of yeast was used, the rate of reaction was the greatest. This means that the enzyme activity is the greatest where the highest concentration of enzyme was used which supports my hypothesis. As the concentration of the enzyme used increases, the enzyme activity also increases. The trial with the least amount of enzyme concentration (only 0.5 mL yeast used) had a rate of reaction value of 0.667 mL/second while the control (1 mL of yeast used) had 0.733 mL/second and the trial with the greatest concentration of enzyme (2 mL of yeast used) had a rate of reaction value of 1.07 mL/second. This difference was significant enough to be able to conclude that increasing

Maltose and sucrose are disaccharide sugars in which a bond joins two monosaccharide molecules. Sucrose is formed by the formation of a bond between carbon 1 of a glucose molecule and carbon 2 of a fructose molecule.

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.

Because there was no oxygen going inside the container, since it was closed with the balloon, there was a great amount of carbon dioxide that was produced. Since oxygen was not present, glycolysis could not go through the citric acid cycle and oxidative phosphorylation. Another aspect of this experiment is the control flask was compared to the flasks that contained the different amounts of sugar, the rate at which the yeast utilized the sugar was a little bit faster in the container that contained more sugar. This is because fermentation requires a sufficient amount of sugar instead of no sugar. Basically, the hypothesis that an increase of sugar added in the closed container containing yeast will produce more carbon dioxide was supported by this experiment. In this experiment, the products that were generated were ethanol and carbon dioxide. Errors in the fermentation process may have been that at the beginning of the experiment, there may have been a little bit of oxygen. It may have gone through cellular respiration, but that may have been extremely quick that it probably does not affect the results greatly. Another error in the results may have also been in terms of measuring the length of the string. When measuring the balloon with the string, the results may have been slightly off a few units. Thus, a more useful tool would be the design of an apparatus with a slight absolute error that record an accurate amount of carbon dioxide

5. Conclusion. In the space below, state whether your data supports or refutes your hypothesis. Conclusions are related to the stated problem and hypothesis and supported by data and scientific concepts.

By changing the pH level of yeast, would it affect its cellular respiration? This experiment would prove that by looking into what conditions yeast best produces carbon dioxide (CO2). The solution of this experiment would be knowing what condition yeast grows best in, and then making it easier to produce more yeast around the world.

Discussion Fermentation Experiment In regards to the fermentation, the more production of gas present, the higher amount of anaerobic respiration occurring. It was hypothesized that glucose would produce the most carbon dioxide since it is a monosaccharide making it the simplest sugar. Following glucose, it was hypothesized sucrose and then the starch since it is a polysaccharide, therefore taking the longest time to form carbon dioxide.

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

Life on this planet began with microorganisms. Through millions of years microorganisms have found ways to successfully adapt and survive. These adaptations have created a wide biodiversity, allowing them to basically populate in all places. Why are these microbes so important? Because they shape the history of our world. Some microbes can be deathly to humans while some others are favorable, for example, bacteria that lives in the gut of both humans and animals and helps during the process of digestion (Alfred Brown & Heidi Smith, 2006). Understanding these interactions help scientists to find ways to protect humans from potential deathly pathogens. In order to observe microbes, microscope proficiency and microorganisms’ identification are crucial skills in a microbiology lab. During this laboratory session, samples of environmental and human organisms were inoculated into two different rich media and incubated to their according temperature. After this, appropriate use and calibration of the microscope was performed. Lastly, morphology and size of different species of bacteria, algae, fungi and protozoan were recorded.

Usually, the clusters produced using thiols are much larger (approx. 25 atoms) than the ones that produced by bottom-up electrochemical and chemical procedures (2 to 20 atoms). The possibility of etching gold nanoparticles by the organic compounds such as thiols and in our case selenols can be assumed taking in consideration the great reactivity of selenol group relative to thiol group and that is the reason of the fast formation of the clusters [28]. These strong binding ligands break the nanoparticles into clusters with 5-9 atoms (top-down clusters-synthesis). TEM images in figure 3 show the etching process of gold nanospheres into gold clusters by using organoselenium compound (1). The compound (1) contains four types of H-bonding, two

Obtain a piece of filter paper. Measure and record its mass, and then place the filter paper on the funnel. Start the vacuum filtration.