C 1.2 Cell Respiration PDF

C 1.2 Cell Respiration “What are the roles of hydrogen and oxygen in the release of energy in cells? “How is energy distributed and used inside cells?” Learning Objectives Include the full name of ATP (adenosine triphosphate) and ATP as the molecu...

C 1.2 Cell Respiration “What are the roles of hydrogen and oxygen in the release of energy in cells? “How is energy distributed and used inside cells?” Learning Objectives Include the full name of ATP (adenosine triphosphate) and ATP as the molecule that that it is a nucleotide. Students should appreciate the C1.2.1 distributes energy within cells properties of ATP that make it suitable for use as the energy currency within cells. Include active transport across membranes, synthesis of Life processes within cells C1.2.2 macromolecules (anabolism), movement of the whole cell that ATP supplies with energy or cell components such as chromosomes. Students should know that energy is released by hydrolysis of ATP (adenosine triphosphate) to ADP (adenosine Energy transfers during diphosphate) and phosphate, but energy is required to C1.2.3 interconversions between ATP synthesize ATP from ADP and phosphate. Students are not and ADP required to know the quantity of energy in kilojoules, but students should appreciate that it is sufficient for many tasks in the cell. Cell respiration as a system Students should appreciate that glucose and fatty acids are the principal substrates for cell respiration but that a for producing ATP within the C1.2.4 wide range of carbon/organic compounds can be used. cell using energy released Students should be able to distinguish between the from carbon compounds processes of cell respiration and gas exchange. Include which respiratory substrates can be used, whether oxygen is required, relative yields of ATP, types of waste Differences between product and where the reactions occur in a cell. Students C1.2.5 anaerobic and aerobic cell should be able to write simple word equations for both respiration in humans types of respiration, with glucose as the substrate. Students should appreciate that mitochondria are required for aerobic, but not anaerobic, respiration. Students should make measurements allowing for the determination of the rate of cell respiration. Students as the molecule that distributes energy within cells Energy in cellular respiration is transferred in small quantities rather than one big release. If energy would be all given out in one go most of it would be lost as heat to the surrounding. Instead, energy is transferred to ATP in many small steps with only little heat loss. as the molecule that distributes energy within cells http://www.uic.edu/classes/bios/bios100/lectures/atp_energy.jpg The nucleotide ATP (Adenosine triphosphate) produced during respiration, is the molecule which directly fuels many biological reactions. It stores What properties chemical energymake in its ATP suitablestructure. as an energy source? It cannot pass through cell membranes, making use within cells controlled It is water soluble, so reactions can happen in the cytoplasm It releases energy in small managable quantities by hydrolysing ATP into ADP – useful for many processes in the cell he third phosphate group is easily removed and re-attached. Energy transfers during interconversions between ATP and ADP Energy is required to build up ATP from ADP. This energy can come from the following processes: Cell respiration, in Hydrolysis which energy is released by oxidizing carbohydrates, fats or Photosynthesis, proteins. in which light energy Condensation is converted to chemical energy Chemosynthesis in which energy is released by oxidizing inorganic substances https://www.dreamstime.com/phosphorylation-atp-adp-cycle-detailed-process-stages-outline-diagram-phosphorylation-atp-adp-cycle-detailed- Energy transfers during interconversions between ATP and ADP Hydrolysis of ATP splits it into ADP by removing one phosphate group with the help of water. Energy contained in the covalent bond is released. The reverse process, where water is released and energy required, is referred to as condensation. http://www.uic.edu/classes/bios/bios100/lectures/atp_energy.jpg ellular Respiration: Uses of ATP Chemical energy (ATP) produced by an organism through cellular respiration can be converted into a number of different forms of energy with only little being lost to heat: The chemical energy stored in ATP can be converted into electrical energy when transmitting a nerve impulse, into kinetic energy during muscle contractions, into light energy in bioluminiscence, into other forms of chemical energy in the synthesis of molecules or when transporting materials. ellular Respiration: Uses of ATP Although there are many uses of ATP in a cell, the three main types of purposes can be summarized below: Synthesizing Movements Active macromolecules transport ellular Respiration: Uses of ATP Although there are many uses of ATP in a cell, the three main types of purposes can be summarized below: Synthesizing Movements Active transport macromolecules  Cellular Respiration as a system to produce The source of organic compounds broken down in cell energy respiration is the food that we eat. Carbohydrates and lipids (fatty acids), but also proteins are used for energy http://2012books.lardbucket.org/books/principles-of-general-chemistry-v1.0/section_22/4d63af61c4222e20 production in cell respiration. Glucose Fatty acids Cell respiration is carried out by enzymes in a careful and controlled way in order to retain it in the form of ATP. The attachment of a phosphate group to ADP to convert it into  http://www.exploringnature.org/graphics/biology/cellular_respiration2_72. Cellular Respiration as a system to produce energyRespiration is not the same as Cellular Breathing! Breathing is the intake of oxygen into the lungs and release of carbon dioxide from Cell respiration is the controlled the lungs to enable gas release of energy from organic exchange and to provide the compounds to produce ATP. It takes Anaerobic and aerobic cell respiration in humans Anaerobic and aerobic cell respiration in humans All forms of cellular respiration start wih glycolysis in the cytoplasm. If oxygen is available aerobic respiration commences. Without oxygen pyruvate will be converted into lactic acid (in humans) during anaerobic respiration. In aerobic respiration substrate are gradually reduced using oxygen as the final electron acceptor. A lot of Anaerobic respiration After glycolysis, pyruvate is broken down in anaerobic cell respiration without using any oxygen. The yield of ATP is relatively small , but the ATP can be produced quickly. This is of importance in particular in following situations: When a short and rapid burst of ATP is needed When oxygen supplies run out in respiring cells In environments which are oxygen deficient (e.g. waterlogged soil)  Anaerobic respiration http://www.workoutstories.com/wp-content/uploads/2008/02/boxing- High intensity exercise such as sprinting, boxing or weight-lifting require anaerobic respiration. This is because…. There is not enough time to deliver O2 to the cells for aerobic respiration. The supply of energy needs to be fast and quickly available so that power Lactate and a small amount of ATP is produced can beThis in this process. maximized. process is only sufficient to produce ATP for ca.2 minutes. Beyond this duration, hydrogen ions (H +) In aerobic respiration oxygen is required and a large amount of ATP is produced If oxygen is available, the intermediate product pyruvate is absorbed by mitochondria Inside the mitochondrion the pyruvate is gradually broken down (reduced) into carbon dioxide, water and 36-38 molecules of ATP. Aerobic cell respiration therefore has a much higher yield of ATP per gram of glucose than anaerobic cell respiration. bic respiration oxygen is required and a large t of ATP is produced 3 transported If oxygen is available, pyruvate is into the mitochondrion, where it gradually broken down into carbon dioxide, water and a large amount of ATP. 1 Glucose from food and oxygen is transported via the bloodstream 2 In the cytoplasm 4 Carbon dioxide is a waste to the cells, where it is glucose is turned into product and diffuses into absorbed into pyruvate during the bloodstream from the cytoplasm. glycolysis. This where it is transported to naerobic versus Aerobic respiration Anaerobic respiration Aerobic respiration Use of oxygen (as electron acceptor) Substrates used Waste products Yield of ATP Location of reactions in the cell Word equation for reaction Purpose of reaction naerobic versus Aerobic respiration easurement of cellular respiration A number of environmental factors affect respiration rate in organism, and for scientists it is often interesting to investigate the factors affecting respiration scientifically. Discuss in groups: 1. How could cellular respiration be measured? http://sites.sinauer.com/animalphys3e/boxex/AnPhys3e-BoxEx-07-04-A-0.jpg 2. What is a rate of respiration? 3. What could be investigated (which factors affecting cellular respiration could be investigated)? asurement of respiration using a respirometer A respirometer is a simple device that is used to measure respiration rate. A respirometer usually involves… http://sites.sinauer.com/animalphys3e/boxex/AnPhys3e-BoxEx-07-04-A-0.jpg The use of a sealed glass container in which the organism is places. A substance which absorbs CO2 produced by cell respiration. A capillary tube containing fluid which allows the changes in pressure to be monitored. asurement of respiration using a respirometer Respirometers can have many shapes and forms. The components and functions of a simple respirometer is shown below. Capillary tube: Thin glass tube filled Syringe: Use to reset with coloured liquid to monitor the the position of the changes in gas volume inside the tubes coloured oil to measure respiration rate. The volume of air inside the container Rubber bungs: seal will reduce due the tubes and close the use of O2 during system airtight to aerobic cell avoid changes in respiration of the volume organisms Metal in it. cage: a platform Temperature for the organism away controlled from the alkali The respirometer Alkali: Usually should be potassium hydroxide immersed in a (KOH) – this absorbs water bath to the CO2 released by prevent temperate the organism during affecting the cellular respiration. pressureand hence This allows to see asurement of respiration using a respirometer 1. Go to this link and open the simulation. Select your preferred type of seed and increase the number of seeds to 25. Make sure to always keep it at this temperature. 2. Select 5°C as the first temperature you will investigate. Click start and wait for the reaction to be complete. Record https://amrita.olabs.edu.in/?sub=79&brch=17&sim=204&cnt= the increase in water level in ml (Look at the initial level of water in the tube!) 3. Repeat the procedure with 5 different temperatures and record the results. Make sure to keep your controlled variables the same. What do you notice? asurement of respiration using a respirometer 1. Describe what factors can be investigated when using a respirometer (independent variables): 2. Explain the need for a base (KOH) inside the respirometer. 3. What direction will the fluid in the capillary tube move if the organisms in the right-hand chamber are respiring and how can this be used to calculate a respiration rate? http://umbrellamarketingteam.com/wp-content/uploads/2015/03/Baby.jpg asurement of respiration using a respirometer When designing an experiment like this, which factors need to stay controlled? What would you do in order to analyze these results? What are ethical implications of the use of invertebrates in respirometer experiments? http://umbrellamarketingteam.com/wp-content/uploads/2015/03/Baby.jpg