The Effect of Different Sugar Sources on Yeast Respiration Essay

This process does not require oxygen and is referred to as fermentation. This process partially breaks down carbohydrates and it obtains a small amount of energy, again in the form of ATP. Pyruvic acid has to be broken down in respiration when formed by breaking down of glucose molecules, this can't be done in the same way as in aerobic respiration. When anaerobic respiration is taking place carbon dioxide and ethanol is formed.

Respiration is a chemical process by which organic compounds release energy. There are two types of respiration reactions that cells use to provide themselves with energy: aerobic and anaerobic (fermentation). (Chemistry for Biologists: Respiration. 2015) Both processes are similar within the initial steps of the reaction- beginning with glycolysis. However, in fermentation instead of the pyruvic acid being converted to acetyl coenzyme A, it’s converted into both ethanol and carbon dioxide in yeast and some plants and lactic acid in animal cells. Another distinct difference between the two processes is that anaerobic respiration uses oxygen

Introduction: Cellular respiration and fermentation are used in cells to generate ATP. All cells in a living organism require energy or ATP to perform cellular tasks (Urry, Lisa A., et al. , pg. 162). Since energy can not be created (The first law of thermodynamics) just transformed, the cell must get its energy from an outside source (Urry, Lisa A., et al. , pg.162). “Totality of an organism’s chemical reactions is called metabolism” (Urry, Lisa A., et al., pg. 142). Cells get this energy through metabolic pathways, or metabolism. As it says in Campbell biology, “Metabolic pathways that release stored energy by breaking down complex molecules are called catabolic pathways” (Urry, Lisa A., et al. pg.

6. Sucrose alters yeast by yeast using sugar as fuel for its fermentation process since sucrose is a sugar.

Determining the effect of varying sucrose concentration on the rate of anaerobic cell respiration in yeasts

The hypothesis of this lab was if yeast is exposed to glucose, fructose, lactose, sucrose and DI water, then the yeast will break down glucose at the fastest rate and produce the most CO₂. This hypothesis was supported by the results of the lab. The results showed that glucose produced the most CO₂ in comparison to the other solutions, supporting the idea that cellular respiration was happening the fastest in the glucose solution. As cellular respiration is occurring, CO₂ is being released into the air. The carbon in the CO₂ is coming from carbons in the reactants of cellular respiration and are released to get rid of excess carbons. By looking at the rate at which carbon dioxide is being produced, the rate of respiration can be identified because the release of CO₂ is a product of respiration

Some cells use aerobic respiration in the presence of oxygen while others use anaerobic respiration, also known as fermentation, in the absence of oxygen. Anaerobic respiration produces fewer ATP molecules than aerobic respiration. Saccharomyces cerevisiae is a type of yeast that can use either aerobic or anaerobic respiration depending on their oxygen availability. Saccharomyces cerevisiae has been essential to baking and wine production. Since carbon dioxide is one of the products of respiration, it can be used to investigate how different kinds of sugar can affect the rate of respiration in Saccharomyces cerevisiae. The rate of respiration in Saccharomyces will be faster in glucose than sucrose because sucrose is a disaccharide and glucose is a monosaccharide. Monosaccharide can produce more carbon dioxide at a more rapid rate than disaccharide (Angustia, Chan, Dinneen, Hortamani, & Mutabaruka

Cellular respiration is a set of chemical transformations in the cell which convert energy gained from food into ATP and then release waste products. In this process, there are two steps, glycolysis, and the Krebs Cycle. . First, the cells goes through glycolysis. One molecule of glucose is converted into two molecules of pyruvate, four molecules of ATP and two NADH molecules as well as water and heat. Then, the pyruvate is sent to the mitochondria, where it is taken apart to produce an acetyl group which joins the enzyme CoA to form acetyl CoA.

Since this lab had two parts to this experiment, it took two weeks to complete it. For this experiment, pages 65-73 in the East Tennessee State University BIOL 1111 Lab book were used for this lab. The first week we measured the rate of respiration in Experiment A. 10mL of yeast suspension was placed into each of the 7 large diameter test tubes. Then after that was completed, six of the seven tubes were filled with a different type of sugar: glucose, fructose, lactose, galactose, sucrose, honey, and the 7th tube were filled with water for the control of this experiment. The tubes were filled approximately ¼ inch below the rim of the tube according to the lab book. After this procedure was completed, all the seven tubes were capped off with

According to the data, all the sugars and stevia could be used by yeast as a food source. This conclusion was reached because all of them produced some CO2 when mixed with the yeast. While they all can be used as a food source, their effectiveness vary. Glucose would be the most effective because it metabolised the most and the fastest. Sucrose produced the second most amount of gas but didn’t start until the 20 minute mark. Sucrose produce the third most amount of gas, however it was metabolised much quicker than fructose, starting at the 5 minute mark and at that point it had metabolised more

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

Yeasts are unicellular fungi that live on fruits, flowers and other sugar containing substrates. Yeast has a high threshold when it comes to a wide range of environmental conditions. Yeast serves a variety of purposing in everyday life. It is used for brewing beer, baking – particularly bread – and cheeses. Enzymes within the yeast break down the sugars such as fructose, glucose and sucrose to produce substances which permits the baking and brewing processes to work. Yeast can tolerate temperatures from freezing to about 55oC, pH levels between 2.8 and 8.0 and can even grow and ferment at sugar concentrations of 3M (high osmotic pressure) .

Cellular respiration makes ATP for animal cells, and photosynthesis makes sugars for plant cells. Respiration starts with glucose undergoing the reactions of glycolysis in the cytosol. The net outcomes of glycolysis are two ATP molecules, two NADH molecules, and two pyruvate molecules. The mechanism for making ATP in glycolysis is called substrate-level phosphorylation. The pyruvate molecules left at the end of glycolysis go on to the Krebs cycle in the mitochondria. At the end of the Krebs cycle, all of the carbon atoms of the glucose have been released as carbon dioxide, and more of the energy that was in the glucose molecule has been saved in the form of ATP, NADH, and FADH2. The last part of respiration is called oxidative phosphorylation, which also happens in the mitochondria.

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

Whereas the large molecule food (Sucrose) will take longer to break down because of its large molecules, this will waste the energy of the yeast as it has to break down the large molecules into smaller molecules before it can use them. This means that the sucrose is not as efficient as the glucose at providing the yeast with a better medium by which it will produce a faster rate of respiration. Theory: