Co2 Lab Report

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

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

For the cell to generate adenosine triphosphate (ATP), plenty of oxygen is needed. Fermentation is a unique way to generate energy ATP in the form of without using any oxygen. Fermentation consists of glycolysis and a process of NAD+ generation. Glycolysis oxidizes glucose to two pyruvate molecules. The two pyruvate molecules are converted into two carbon ethanol molecules, and two carbon dioxide molecules are released. The overall net yield of fermentation are two ATP molecules and two NADH

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 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.

4. Fructose is component of sucrose, normal table sugar, along with glucose. Whereas glucose is able to immediately enter into glycolysis, fructose is not. Fructose is broken down via fructokinase into fructose- 1-phosphate. Fructose – 1-phospate then gets converted into DHAP+ glyceraldehyde via aldolase B. DHAP+ glyceraldehyde is used in glycolysis to produce pyruvate that goes into the citric acid cycle to produce ATP

At the end of 60 minutes, test tube 1 ,2, 3, 4, 5 and 6 produced 47 mm, 33 mm, 4 mm, 4 mm, 9 mm and 46 mm of CO2, respectively. The amount of CO2 produced tells us that there was a high rate of cellular respiration in test tube 1, 2 and 6 and there was a low rate in test tube 3, 4 and 5. As shown on the graph, there is a steeper slope for test tube 1, 2 and 6 and gentle slope for test tube 3, 4, and 5. The steeper the slope the faster the rate of CO2 produced. The test tubes 1, 2 and 6 had high rate of respiration because of the presence of glucose, maltose and MgSO4, respectively. Both glucose and maltose is able to give more amount of CO2 than any other substrate. MgSO4 is a cofactor and the presence of the cofactor allows better formation of pyruvates resulting in a higher rate of cellular respiration. The test tube 4 had a low rate because it contained no substrate for respiration, there was only water. There was a low rate in test tube 5 because of the presence of NaF. NaF is an inhibitor and have the capacity to interfere with the enzymatic activity. The presence of alanine will result in low rate of cellular respiration as seen on test tube 3 because alanine has least amount of carbon in

 produced per minute. The results show a trend wherein increased concentrations of sucrose increase the rate of cellular respiration.

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.

Test tube 7, Sucrose, produced 8 mL of CO₂ and test tube 8, fructose, produced 5.5 mL of CO₂. In addition, test tube 9 had a 7mL production of CO₂. Test tube 9, lactose, had 0 mL production of CO₂. Lastly, test tube 11, lactose +Lactaid produced 7 mL of CO₂.

Since we obtain a p-value higher than 0.05, we accepted our null hypothesis that states, “there is no different between the different sugars utilize and higher population growth of yeast”. According to the scientific journal by fonseca, fructose should of yield a higher yeast concertation, since fructose can be directly incorporated into the glycolysis reaction. Fructose is a monosaccharide, so it doesn’t utilize energy to hydrolysis a reaction. On the other hand, galactose is a disaccharide which requires energy in order to be hydrolysis into a monosaccharides. The hydrolysis of galactose to a monosaccharide is tends to be a slow reaction.

The natural sugars used in this experiment will be lactose and glucose. The unnatural sugar that will be used is saccharin (an artificial sweetener). The rate of cellular respiration between the natural sugars will be compared to that of the unnatural sugar. Yeasts are unicellular organisms that belong to the fungi kingdom. Yeasts are known as facultative anaerobes; they can respire depending on the environment they are in. Yeast can metabolize sugars aerobically or anaerobically. In both cases, Carbon dioxide is produced.

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

One of the most fundamental processes of life is the ability to turn sugar into energy. Our cells have the ability to carry out this process both aerobically and anaerobically. Although anaerobic respiration does not produce the amount of energy that aerobic respiration does; it is still a very important process, because it allows cells to turn sugar into useable energy in the absence of oxygen. (Lab 15: Fermentation Experiments: Background) This is done though a process called fermentation. “Fermentation consists of glycolysis plus reactions that regenerate NAD+ by transferring electrons from NADH to pyruvate.” (Campbell and Reece 173-178) There are many different types but we happen to be interested in alcohol fermentation, which is carried out by bacteria and yeast. (Reiner) In alcohol fermentation sugar is broken down and turned into carbon dioxide and ethanol. Knowing this we can measure the amount of carbon dioxide produced and get an idea of how quickly the reaction is running. (Campbell and Reece 173-178) Glucose is one of the most abundant carbohydrates on earth and therefore is generally the sugar involved in fermentation. (Ophardt) It is a monosaccharide with a “six membered ring structure” ("Simple Sugars: Fructose, glucose and sucrose") Fructose and sucrose are two other common simple sugars found in many of the foods we eat. Fructose is very similar to glucose only it is made up of a five membered ring. And sucrose is a disaccharide; it is a combination

As the diagram on the right displays, one molecule of Glucose produces two molecules of carbon dioxide and two molecules of ethanol. The fermentation of glucose to ethanol is only possible if oxygen is absent otherwise instead of producing ethanol and carbon dioxide, lactic acid is produced instead.