Index IntroductionMaterials and methodsResultsResults of fermentation reactions:Results of cellular respiration reactions.DiscussionQuestion from the lab manualErrors/Future experimentsThe purpose of this lab was to observe fermentation in yeast with different carbohydrates at different temperatures and cellular conditions respiration of lima beans with different quantities of the necessary reagents. It was observed that fermentation reacted at a slower rate than cellular respiration. It was also observed that fermentation was more effective with glucose at a temperature of 37°C. It was determined that respiration was most efficient with 150 µL of DPIP, 150 µL of mitochondrial suspension, and 200 µL of succinate. The slower fermentation rate is caused by the lack of the electron transport chain present in cellular respiration. Say no to plagiarism. Get a tailor-made essay on "Why Violent Video Games Shouldn't Be Banned"? Get an original essay IntroductionCellular respiration is the process used by cells to convert and break down organic substances, such as glucose, to release energy that the cell can use to function. Glucose is an important part of this reaction because it is what all products are derived from, without it there would be no respiration; it is also the most efficient carbohydrate to use. Cellular respiration has multiple parts where redox reactions are used to create ATP. Respiration occurs in different parts of the cell in some parts of the process. The reaction begins in the cytoplasm but will eventually move to the mitochondria. These pathways allow ATP to be produced in the cell where it is needed and therefore there will be no need to transport it elsewhere in the cell. Oxygen is necessary in cellular respiration making it an aerobic reaction. Oxygen is needed to “pull” electrons along the electron transport chain at the end of respiration. This results in the formation of H2O and ATP molecules. The following equation describes the complete reaction of cellular respiration C6H12O6 + 6O2 is 6CO2 + 6H2O + energy (about 36 ATP). It is clear that oxygen is an important part of this process, which is why most organisms need a constant supply of oxygen (Upadhyaya). When oxygen is not available, breathing is still necessary for an organism to have energy to function. This type of breathing is called fermentation. Organisms that do not have access to oxygen must use fermentation. Fermentation begins as a part of cellular respiration called glycolysis. This part of cellular respiration does not use oxygen but uses redox reactions to create small amounts of ATP. Yeast is an example of an organism that can switch from respiration to fermentation. In this laboratory, yeast fermentation is observed. The type of fermentation used by yeast is called alcoholic fermentation because one of the products of this process is alcohol. This process is described by the following equation. C6H12O6 is 2C2H5OH + 2CO2 + energy (2 ATP) (Upadhyaya). Another type of fermentation is lactic acid fermentation where the byproduct is lactic acid. This reaction often occurs in muscle cells that need to generate energy much faster, such as during exercise. Animals generally use cellular respiration but use fermentation if necessary, while only organisms without access to oxygen always use fermentation. This lab was conducted in two separate parts, the first looking at fermentation in the east and the second looking at cellular respiration in the mitochondria ofLima beans (Upadhyaya). It is important to understand these two processes to know how organisms acquire and use the energy needed to live. The two parts of this laboratory observed these two types of metabolic reactions under different conditions with different amounts of reagents. The different amounts of reactants were expected to change the reaction rate somewhat. With fermentation reactions, the lower temperature was expected to slow or hinder the reaction while the higher temperature was expected to speed up the reaction. The fermentation reaction with three different carbohydrates was also observed in an attempt to determine which was best for yeast fermentation. The respiration portion of this lab looked at respiration rates for different amounts of reagents. The reaction rate was determined using a spectrophotometer. The DPIP reagent is blue before respiration occurs. However, during the reaction DPIP acts as an oxidizing agent and accepts an electron from succinate during a redox reaction. A redox reaction occurs when a molecule gives up an electron to another molecule, reducing and oxidizing it. When this reduction in DPIP occurs, the chemical changes from colorless. Using the spectrophotometer it is possible to measure the absorbance of DPIP thus determining how much reaction has taken place. One can hypothesize that for part 1 37 degree glucose will be the most efficient because glucose is the best carbohydrate for respiration and 37 degrees is very close to the optimal temperature. For part 2 it is assumed that the sample with the greatest amount of succinate will be the most efficient because it will have the greatest number of electrons to give to DPIP. Materials and methods Three different solutions and one control (water) from the laboratory were used for this part, all solutions were each kept at three different temperatures, 4°C, ~25°C (room temperature) and 37°C. The researchers used a pipette to place 15 ml of each solution into 50 ml beakers. The researchers then measured out 0.5 grams of yeast and mixed it with each solution. After the yeast was thoroughly mixed with the solutions, the mixture was quickly transferred to the fermentation tube. The tube was then inverted to make sure all the air had escaped. The 4°C tubes were placed in the refrigerator while the 37°C tubes were placed in an incubator. The amount of CO2 formed in the tube was measured every five minutes for forty minutes. The spectrophotometer was turned on and set to read the percentage of transmittance at 600 nm. 6 tubes were labeled B1, B2, 1, 2, 3 and 4. The researchers prepared the two blanks, B1 and B2, according to the table below. After preparing the blanks the spectrophotometer was darkened with B1 and the other four tubes were prepared according to the table, adding the succinate last. After the succinate was added, parafilm was placed on top of the four tubes and they were shaken for another two seconds. Tubes 1, 2 and 3 were inserted into the spectrophotometer after capping it with B1. The spectrophotometer was then darkened with B2 and tube four was placed in the spectrophotometer. This process of testing the tubes was repeated every five minutes for thirty minutes. Figure 1- This figure shows how each of the 6 tubes was prepared for the cellular respiration reactions. Results Results of the fermentation reactions: Figure 2 (Effect of food source and temperature on CO2 production)- This table shows the results of the fermentation reactions. Figure 3- This graph shows the reaction results for each food at 37 degrees Celsius. Figure 4-This graph shows the reaction results for each course of food at 25 degrees Celsius. Figure 5- This graph shows the reaction results for each course of food at 4 degrees Celsius. These four figures represent the same information just in different forms. Figure 2 shows that by far the most efficient conditions for yeast fermentation were with glucose at 37 degrees. The figure also shows that control samples containing only water did not have any type of reaction. Furthermore, it is clear that the colder samples did not ferment very well either. Results of cellular respiration reactions. Figure 6 (Results of Cellular Respiration Reactions) - This table shows the % transmittance of each sample at a wavelength of 600 nm for forty minutes. Figure 7-This graph shows the percentage of transmittance for each sample (1, 2, 3 and 4) over the forty minutes in which the reactions took place. Figure 8 (Initial Reaction Rate of Cellular Respiration) - This figure shows the initial reaction rates by identifying the slope of the lines on the graph. The first two figures show that the contents of sample 3 produced the most efficient reaction as it had the highest transmittance percentage. Furthermore it is clear that sample 4 had almost no continuous reaction. Discussion Based on the results from part 1 of this lab it is easy to see that the most efficient condition for yeast fermentation is 37 degree glucose. This result occurred because glucose is the main source of fuel for respiration. Glycolysis, which is used by fermentation, works better and more efficiently with sugar glucose. Starch and sucrose, although they work for fermentation, do not ferment as well, resulting in the production of much less ATP or CO2. The temperature at which the reaction occurs also plays an important role in the amount of reaction. Fermentation often occurs inside the body of an organism, which is generally a warmer environment; therefore the optimal conditions for any type of breathing would be in warmer environments. The reaction simply did not take place at a level near zero because chemical reactions generally require thermal energy to occur efficiently (Clark). In the cellular respiration portion of this lab, samples 1, 2, and 3 all contained equal parts mitochondrial suspension and DPIP. However, samples 3 and 2 were much more successful in their reactions, with 3 being the most successful. The difference between these three samples was their succinate level, with 3 having the highest, 2 the second highest, and 1 the lowest. This shows that the amount of succinate is very important in the cellular respiration reaction. This supports the hypothesis because it was hypothesized that the sample with the highest succinate would react more because it would have the greatest ability to oxidize and give electrons to the DPIP. The fourth sample was by far the least responsive. This is because sample 4 did not contain any mitochondrial suspension, meaning there was no strong environment for the reaction to occur. Overall it can be concluded that for yeast fermentation, warmer temperatures with glucose are the most efficient and that a higher amount of succinate is useful for cellular respiration. Question from the lab manual The addition of succinate was crucial in reducing DPIP. Without it, as in sample 1, the reaction was minimal compared to samples 2 and 3, which contained large amounts of succinate. It is clear that the mitochondria were breathing. If the mitochondria did not respire, DPIP would not have undergone reduction..