Lab Report Yeast Fermentation

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.

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.

In this activity two sets of experiments are performed to determine the rate of cellular respiration by measuring the amount of CO2 in fermentation tube. Larger the rate of cellular respiration, larger will be the amount of gas produced. To conduct the experiment yeast and water were added together at first. Yeast mixture was poured into the test tube and another test tube on the top. After flipping the tube upside down the amount of gas produced was observed at the top of Tube for about 10 minutes to determine the Cellular Respiration Rate.

The research question asks how varying sucrose concentrations affect the rate of anaerobic cell respiration in yeast, measured in CO2 production. The rate of anaerobic respiration will be determined by measuring the rate of CO2 production by the yeast cells.

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.

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.

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

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

Hypothesis: The yeast will have a greater rate of respiration for the natural sugars specifically the glucose and lower rate of respiration for the unnatural sugars

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

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