Abstract Cellular Respiration, a process by which an organismproduces energy from energy molecules such as glucose orfatty acids, occurs differently under certain conditions. Thisreport makes use of these differences by exposing yeastsuspension under different conditions.
5 Smith Fermentation tubes wereprepared and placed with glucose withyeast, glucose, boiled yeast withglucose, starch solution with glucoseand yeast respectively. The rates ofCO2 formed by the yeast in each tubewere compared for 40 minutes.
Abstract It can be concluded that under the condition by whichyeast and a simple sugar such as glucose is present, theproduction of CO2 will form more prominently than theothers.
I. Introduction All organisms need energy to survive. Cells use aprocess called Cellular Respiration to acquire the energyneeded. In Cellular Respiration an organism’s cells transformsenergy molecules like starch or glucose into an energycurrency called Adenosine Triphosphate or ATP.
I. Introduction Cellular Respiration can be classified as Aerobic orAnaerobic Respiration. In Aerobic Respiration, cells willbreakdown glucose in the presence of oxygen through certainprocesses to produce CO2 and H2O. Aerobic Respirationusually occurs within the cells of animals such as humans.
I. Introduction On the other hand, Anaerobic Respiration which can bedivided further more into Alcoholic Fermentation or LacticAcid Fermentation occurs without any oxygen. The onlydifference between the two processes is that AlcoholicFermentation produces ethanol, ATP and CO2 while LacticAcid Fermentation produces Lactic Acid and ATP.
I. Introduction In terms of completeness in breakdown and productionof energy and CO2, Aerobic Respiration is complete andproduces 6 moles of CO2 and 36/38 ATP while Fermentationproduces 2 ATP and 2 moles of Lactic Acid (Lactic AcidFermentation) or 2 moles of CO2 and a mole of ethanol.
I. Introduction The experiment conducted aims to study the cellularrespiration in yeast by observing the results and taking noteof the condition at which they occur. Also, this experimentaims to enumerate factors in cellular respiration by analyzingand varying the reagent in each smith fermentation tube.
• 5 Smith Fermentation tubes were filled with 20 ml of different reagents. (Glucose for the first 3 tubes, Starch for the 4th and water for the test tube • 20 ml water was added to each of the tubes.II. Methodology • 20 ml of yeast suspension was added to tubes 1,4 and 5 while 20 ml of boiled yeast suspension was added to tube 3. • Each tube were checked for air bubbles in the tube and titled the tube horizontally while covering the opening to remove them. • The opening of each tube was covered with cotton. • The evolution of CO2 in each tube were recorded and compared.
III. Results and Discussion Cellular Respiration is spontaneous chemical processwherein a cell makes energy by the transformation of energymolecules such as sugars and fatty acids into ATP and certainby-products. Cellular Respiration is divided mainly intoAerobic Respiration and Anaerobic Respiration.
Aerobic Respiration is the creation of 36/38 units of ATP, 6 moles of CO2 and 6III. Results and moles of H2O from the breaking down ofDiscussion glucose through certain processes. It is given by the equation: C6H12O6 + 6O2 6CO2 + 6H2O+ 36/38 ATP
Aerobic Respiration is divided into 3III. Results and major processes: Glycolysis, the KrebsDiscussion Cycle and the Electron Transport Chain. The first step of any type of Cellular Respiration is Glycolysis where the glucose molecules are transformed into 2 moles of pyruvic acid in the cytosol at the consequence of using 2 units of ATP.The energy input and output of glycolisis
III. Results and In this process, 4 units of ATP is produced for a Discussion net total of 2 (subtracted from the 2 used), 2 units of NADH+H and as said, 2 moles of pyruvic acid. The pyruvic acid produced goes into a transitional stage where the pyruvic acid is transformed into Acetyl CoA. This product then goes into the Kreb’s cycle where Acetyl CoA goes through numerous transformations which will result into 8 units of NADH, 2 units of FADH2 and 4 units of ATP. This whole process occurs inside the mitochondrial matrix of the cell.Overview of pyruvate oxidation and Citric AcidCycle
III. Results and Lastly, the units of NADH and FADH2 proceed to Discussion the cristae of the mitochondria where these products are passed through certain pigments called cytochrome. These carriers are then transformed into ATP. The total units of ATP produced is 36 or 38 units this is called the Electron Transport Chain. The reason for the difference is due to the transportation of the NADH produced in the cytosol to the mitochondrion of the cell. There are 2 transportation systems: malate aspartate and glycerol phosphate.Free-energy change during electron transport
III. Results and Discussion Under malate aspartate NADH can pass through the completeTransport chain thus producing 6 for the two NADH while in glycerolphosphate it will produce 4. Anaerobic Respiration on the other hand is the production ofEnergy from the enzymatic breakdown of Glucose to produce energythis process is done without oxygen.
III. Results and Discussion Unlike its oxygen using counterpart, Anaerobic Respiration is muchmore inefficient in the production of ATP producing just 2 units of ATP. InAnaerobic Respiration, only glycolysis takes place and the NADH producedwill be used in the repetition of glycolysis. This process has two differenttypes: Alcoholic Fermentation and Lactic Acid Fermentation. AlcoholicFermentation is the production of Ethyl Alcohol, 2 moles of CO2 and 2 unitsof ATP.
C6H12O6 2CO2 + C2H5OH + 2 ATPThis type of respiration occurs in yeast and some plant cells.
III. Results and Discussion The other type of Anaerobic Respiration is Lactic acid Fermentationwhich is the enzymatic breakdown of glucose into Lactic acid and 2 units ofATP. It is given by the equation: C6H12O6 → C3H6O3 + 2 ATP This type of respiration is seen in bacteria and muscle cells. This isthe main reason for cramping in our muscles
III. Results and Discussion In Cellular Respiration, there are two processes which can be observed in theproduction of energy. The first is called substrate phosphorylation. It occurs when amolecule of ADP reacts with a phosphate group from a substrate to produce ATP. Thistype of Phosphorylation is seen in Glycolysis and also in the Kreb’s Cycle. The other type of phosphorylation is called Oxidative Phosphorylation. This isthe process that creates the most number of ATP. This is only seen in AerobicRespiration and it occurs when an ADP combines with a phosphate group in theelectron transport chain.
min. 1 2 3 4 5 5m 0.02mm n/a 0.15mm 0.08mm 0.1mmTube No. Contents (excluding H2O) 10m 0.03mm n/a 0.18mm 0.10mm 0.1mm 1 Glucose +Yeast 15m 0.04mm n/a 0.20mm 0.10mm 0.1mm 2 Glucose 20m 0.05mm n/a 0.21mm 0.14mm 0.1mm 3 Boiled Yeast + Glucose 25m 0.05mm n/a 0.24mm 0.15mm 0.1mm 4 Starch Solution + Yeast 5 Yeast 30m 0.05mm n/a 0.25mm 0.15mm 0.1mm 35m 0.5mm n/a 0.25mm 0.20mm 0.1mm 40m 0.5mm n/a 0.26mm 0.20mm 0.1mm In the experiment, mixtures were placed in separateSmith Fermentation tubes. The diameter of the circle wasmeasured to compare the amount of carbon dioxide formed.
After shaking vigorously, spontaneous production of CO2 was observed. Since itIII. Results and produced bubbles instead of one big bubble, theDiscussion amount was then just compared to one another. Content Amt. of bubbles Glucose +Yeast Large production Glucose No Bubbles Boiled Yeast + Glucose 1 small bubble Starch Solution + Yeast 2 large bubbles with a small prod of bubbles Yeast No Bubbles
The production of CO2 was observed inIII. Results and Tube 1, Tube 3 and Tube 4.Discussion The evolution of CO2 is very fast and the bubbles were numerous in tube 1 this was because glucose was readily available for the respiration of the yeast. In tube 3, there should be no CO2 because yeast dies in high temperature. The presence of CO2 in tube 3 is probably due to the incomplete heating of the yeast suspension.
III. Results and Discussion Lastly, in tube 4 there was little evolution of CO2 this is becauseto respire, yeast must secrete amylase to break down the starch intoglucose and not all yeast can produce amylase and even if they couldthis will take more time. For tubes 2 and 5 Respiration was not presentbecause one of the essential factors was absent (yeast in tube 2 andglucose in tube 5).
III. Results and Discussion There are several factors in which respiration will occur, let’sdiscuss them one by one:
III. Results and The more nutrients that is available to transform, the Discussion more energy results in the cellular respiration process. The types of nutrients that can go through the cellular respiration process and transform into energy are namely fat, proteins and carbohydrates. This also includes amino acids and fatty acids. The carbohydrates converts to glucose, the fats go through the citric acid cycle and the proteins break down and go through glycolysis. The amount of nutrients available to transform into energy depend on the diet of a person. The nutrients go through three processes in cellular respiration.Amount of The processes are glycolysis, Kreb’s cycle and the cytochrome Nutrients system.
Another factor affecting the cellular III. Results and Discussion respiration is the temperature of the environment. Usually, the rate of cellular respiration quickens if the temperature is warmer. The lower the temperature, the slower the rate of cellular respiration is. People who live in warmer environments find it easier to restore their energy as long as there are nutrients available to convert in the body.Temperature
The reason for this is the enzymes that III. Results and are present in the cellular respiration process. Discussion Enzymes break down easier and then transform into energy quicker when the temperature is higher. Although the temperature affects the rate of cellular respiration, there are no studies that prove more energy production with higher temperatures. The temperature factor just affects the rate of the cellular respirationTemperature process.
III. Results and The state of a cell undergoing the cellular respiration Discussion process is a factor that affects the rate of transforming nutrients into energy. Working cells, such as neurons or roots of the human hair, have a higher cellular respiration rate compared with dormant cells like seeds. This is because working cells can store extra energy in the body while dormant cells tend to stay non-motile. For this reason, plant cells do not need to store as much energy as human cells or animal cells do. This is the reason why cellular respiration in plants is a bit different from the cellular respiration process human State of and animal cells go through. Cell
III. Results and As seen with the experiment the type of Discussion substrate to be used in Respiration is quite important. As for the case of the yeast, if glucose, starch and maltose are placed in different tubes, glucose will still be the fastest. Though there are numerous glucose molecules in both maltose and starch, the yeast will need to release enzymes which may not be available to them and even if they are itSubstrate would take time compared to an environment Present where glucose is readily available.
III. Results and In the experiment, yeast was observed to use Discussion energy through Alcoholic Fermentation. Though yeast can produce through both Aerobic and Alcoholic Fermentation, it can be deduced that it is anaerobic because the cotton was placed to block any oxygen had there been oxygen the amount of CO2 would have been much greater.Substrate Present
IV. Conclusion The rate of cellular respiration is affected by the conditions inwhich it takes place. When yeast and a simple sugar such as glucose ispresent during the cellular respiration, the production of CO2 will formmore prominently than the others
Biology 10 (General Biology) Laboratory Manual. Department ofBiology - College of Arts and Sciences - University of the Philippines, Manila. Print. Campbell, N.A., Reece, J.B. & Meyers, N. (2006). Biology. Frenchs Forest: Pearson Education Delos Reyes, J. (2006). Introduction to Biology: Principles and Processes (6th ed.). Department of Biology, College of Arts and Sciences, University of the Philippines Manila. References