Strain Saccharomyces Cerevisiae Lab

The purpose of this investigation is to test the effect of different sugar sources on yeast respiration.

Hypothesis: If the concentration of an substrate is increased then the time it takes for the yeast spheres to rise will decrease because there is more substrate for the enzyme to break down, creating more oxygen, faster.

Yeast is a fungus that can generate glucose into energy without using any oxygen molecules. We tested the fermenting ability of yeast from two different carbon sources: glucose and aspartame. We hypothesized that yeast is unable to use the carbon sources of aspartame. To do this, we decided to use both carbon sources in the same concentration. Each carbon source was mixed with the same amount of yeast solution. The experiment group of 5.5 mM aspartame solution was compared with the control group of 5.5mM glucose solution. We recorded the rate of fermentation for glucose and aspartame in the Vernier Lab Quest. The fermentation rate of aspartame is a negative number, and glucose is a positive number. Our results show that yeast was unable to ferment aspartame as yeast fermented glucose. The results indicate that aspartame has no effect on yeast fermentation rate because yeast do not catabolize aspartame because it does not have the appropriate enzymes to break it down.

2) Yes, the rate of gas production increased as more yeast was added, since more enzyme was able to convert hydrogen peroxide more quickly.

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.

Citrobacter Freundii is a species of bacteria that can be potentially harmful to humans. It is known to cause meningitis by protruding into the brain and replicating itself (1). The Citrobacter species has also been found as a cause of some urinary tract infections, diarrhea, and even gastrointestinal diseases and symptoms (3). C. Freundii can be located in a wide variety of soils and water (3). Lastly, it is also the cause of many nosocomial infections due to its presence in water (1).

In this lab we tried to find what fuels yeast could metabolize and what the yields of the carbon dioxide gas that were produced from the different sugars used. We used 6 different yeast and sugar mixtures. The different yeast and sugar mixtures we used were control, glucose, sucrose, fructose, starch, and saccharin. The results for the 6 different results are presented in Tables 1-6 and Graph 1. Graph 1 is a graph of all the information in Tables 1-6. Each Table and graph is labeled approximately.

This lab investigates the effects of Sucrose concentration on cell respiration in yeast. Yeast produces ethyl alcohol and CO2 as a byproduct of anaerobic cellular respiration, so we measured the rate of cellular respiration by the amount of CO2

Higher levels of solution should produce higher levels of product. The independent variable for the control group data and the experiment data is the yeast concentration. The dependent variable for the control group data and the experiment data is how much oxygen is produced. The Constant for the control group data and the experiment data is time and amount of hydrogen peroxide. The products of the experiment will increase if the levels of reactants increase. Denatured yeast may cause change in the reaction of the experiment. For all trials of the control group, the concentration of yeast is 6ml. For the experiment data, the yeast concentration varies from 8mL, 10 mL, 12 mL, 14 mL, and 16 mL. The temperature may cause change in the reaction of the combination of yeast and hydrogen peroxide

C. elegans was maintained on Escherichia coli OP50 as described.25 C.elegans strains used in this study were wild-type N2, mir-252(n4570), and lys-8 mutant (n?). C. albicans strains used in this study was SC5314 (clinical isolate), a strain that is virulent toward C. elegans, 26. All the used mutants were backcrossed to N2 for at least five times. Double mutant strains without additional marker mutations were constructed using standard genetic methods and verified by complementation testing. At least five independent lines were examined for each rescue experiment. Unless otherwise specified, C. albicans SC5314 was used as the wild-type strain. Yeast strains were grown in liquid yeast extract-peptone-dextrose (YPD)

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

Table 1: Table of Results Showing the Effect of Yeast Mass on the Rate of Yeast-Facilitated Fermentation of Glucose

Brittney Tokarick Dr. Yorty Bio111 – Lab November 5, 2014 CO2 Evolved due to Temperature’s Effect on Yeast Fermentation of Glucose Abstract This experiment measured the amount of CO2 evolved based on yeast fermentation of glucose. It was hypothesized that at room temperature, about 22 degrees Celsius, less CO2 would be produced than when tested at 37 degrees Celsius. In order to determine the amount of CO2 evolved, an experiment was set up involving yeast, glucose, deionized water, and heat.

A sterile pipette was used to add 0.1ml of E. coli culture to the pH 3.0 tube. This was then repeated for the tubes at pH 7.0 and pH 9.The tubes were then incubated at 37oC for 48 hours. This was then repeated for saline culture of Saccharomyces cerevisiae but incubated for 72 hours at 25oC.