Cellular Respiration, Study Guides, Projects, Research of Design

Download Cellular Respiration and more Study Guides, Projects, Research Design in PDF only on Docsity! Cars need energy to move. A mixture of oxygen and gasoline, when ignited by y= a spark, produces a small, controlled explosion in ~ CAN YOU EXPLAIN IT? the engine's cylinder that Drea Both cars and your body need fuel. Most cars use gasoline as a fuel, which often includes ethanol in addition to gasoline. For a car or a human body to use fuel, the energy in the chemical bonds of the fuel must be released. A combustion reaction ina car's engine releases this energy. Your body uses a similar reaction in which it releases the energy contained in the chemical bonds of the food you eat. Gather Evidence As you explore the lesson, gather evidence that bonds are broken and new bonds are formed in the process of cellular respiration. FIGURE 1: The ignition of a mixture of ethanol and oxygen in the air produces a combustion reaction, which releases energy in the forms of heat and light. ) Houghton Mifflin Harcourt Predict How is the process of fuel combustion in a car engine similar to the way the cells in your body release energy stored in fuel? Image Credits: (t) ©Cultura/Echo/Getty Images; 128 — Unit3 Matter and Energy in Living Systems EXPLORATION 1 Matter and Energy in Cellular Respiration Fuel is any material that reacts to release energy to be used for work. Not all fuels are alike. They have many different chemical structures. Analyze Howare glucose and ethanol similar $ instructure and function? How do " FIGURE 2: Ethanol isa fuel made they differ? oe from plant material, such as corn. io Asa renewable energy source, A \y it helps reduce petroleum use. \ on 4 /I 4 Glucose is a simple sugar that H—-0 o-H fii 4 ' : a living things use for energy. 4 o-H HOH Glucose Ethanol Energy in Living Systems Whether food for organisms or fuel for cars, almost all the energy on Earth has its origins in the sun. In the process of photosynthesis, plants transform light energy from the sun into chemical energy in the form of glucose. When an organism eats a plant, any energy the plant has not used can be used by the consumer. Ancient plants and animals that died decomposed and were buried under soil, rock, and sometimes sea water. These organisms decomposed into organic materials that contain unused stored energy. Over millions of years, heat and pressure transformed these remains into the fossil fuels we use today. Chemical bonds must be broken for the stored energy to be released. In cars, a combustion reaction provides the energy needed to break these bonds and release energy. In cells, a similar process called cellular respiration releases chemical energy from sugars and other carbon-based molecules to make ATP when oxygen is present. Poa a Cal Co) FIGURE 3: Activation energy is the energy needed to start achemical reaction. An exothermic reaction releases more energy than it absorbs. Cellular respiration is an exothermic. reaction. activation energy reactants Energy —» | difference in energy products Reaction progress —> Gather Evidence Explain why cellular respiration is an exothermic reaction. Cite evidence from the graph shown in Figure 3 to support your explanation. Lesson 2 Cellular Respiration 129 Seen _ Cellular Respiration and Photosynthesis ® EL em e-Le) Almost all energy for living things comes from photosynthesis, either directly or indirectly. Producers absorb light energy from the sun and transform it using photosynthesis to a usable form of energy, or food. This energy is then passed from producers to consumers. Although only producers carry out photosynthesis, both producers and consumers carry out cellular respiration. Photosynthesis stores energy from sunlight as chemical energy. In contrast, cellular respiration releases stored energy as ATP and heat. Investigating Photosynthesis and Cellular Respiration Design an experiment to determine which organisms (pond snails or Elodea) produce carbon dioxide and which use carbon dioxide. FIGURE 7: A Comparison of Photosynthesis and Cellular Respiration Photosynthesis light energy REACTANTS PRODUCTS CO, : > CoH 206 1,0 > mm> 0, Analyze Whatis the relationship between the inputs and outputs of photosynthesis and cellular respiration? Cellular Respiration PRODUCTS REACTANTS CO; <== ee Got0 H,0 <jem = ©, heat SAP {z] Model Sort the following terms into those that occur during photosynthesis and those that occur during cellular respiration. Then place the terms in the correct order. + absorption of sunlight + ATP production + production of sugars + breakdown of sugars 132 Unit3 Matter and Energy in Living Systems EXPLORATION 2 Using Chemical Energy One way that organisms maintain homeostasis is through cellular respiration, which releases energy to carry out cell processes and helps maintain body temperature. Bonds in food molecules and oxygen molecules are broken and new molecules are formed that transfer energy in forms that the organism can use. Cellular respiration transfers chemical energy stored in the bonds of glucose and other molecules to ATP. Analyze Identify the inputs and outputs of glycolysis and the two stages of cellular respiration. 2 FIGURE 8: The process of glycolysis occurs before the two main stages of cellular respiration: the Krebs cycle and the electron transport chain. electrons cartied in NADH pyruvate electrons cartied ~ in NADH and electron transport chain FADH, glucose =| glycolysis mitochondrion Glycolysis and the Stages of Cellular Respiration Cellular respiration occurs in mitochondria. Before it can take place, however, glucose must be broken down into compounds the mitochondria can use. This process occurs in the cytoplasm of the cell. Glycolysis, shown in Figure 9, is an anaerobic process that uses a series of enzyme-catalyzed reactions to break glucose into two three-carbon molecules, called pyruvate. Mitochondria use the pyruvate molecules to fuel cellular respiration. FIGURE 9: Glycolysis He” easel: glucose ADP Sie °f 2 pyruvate NAD* Gather Evidence Summarize evidence that bonds are broken and new bonds are formed in glycolysis. Lesson 2 Cellular Respiration 133 between the energy in sugars and energy-carrying molecules? 134 Analyze Howisthe Krebs cycle a bridge Unit 3 Matter and Energy in Living Systems Krebs Cycle The Krebs cycle, sometimes called the citric acid cycle, is the first set of reactions in cellular respiration. The function of the Krebs cycle is to complete the breakdown of glucose started in glycolysis and fuel the production of ATP. This is done by transferring high-energy electrons to the electron transport chain. FIGURE 10: The Krebs Cycle TOO pyrite NAD* mom «| * iz Coenzyme A [NAD] NAD* citric acid 3 FAD NAD+ 4 6 CBBB, so NADH ‘compound Ge6G6O0 5-carbon ‘ADP compound 5 SHE £0, HD N10" The Krebs cycle is summarized in the steps below. 1 Pyruvate is broken down A 3-carbon pyruvate molecule is split into a 2-carbon molecule and a carbon dioxide molecule, which is given off as waste. High-energy electrons are transferred to NAD", forming a molecule of NADH. The NADH moves to the second stage of cellular respiration, the electron transport chain. Coenzyme A is added A molecule called coenzyme A bonds to the 2-carbon molecule, forming an intermediate molecule. Citric acid is formed The 2-carbon part of the intermediate molecule is added toa 4-carbon molecule to form the 6-carbon molecule called citric acid. Citric acid is broken down The citric acid molecule is broken down by an enzyme, and a 5-carbon molecule is formed. A molecule of NADH is made, which moves out of the Krebs cycle. A molecule of carbon dioxide is given off as a waste product. Five-carbon molecule is broken down The 5-carbon molecule is broken down by an enzyme. A 4-carbon molecule, a molecule of NADH, and one ATP are formed. Carbon dioxide is given off as a waste product. Four-carbon molecule is rearranged Enzymes rearrange the 4-carbon molecule, releasing high-energy electrons. Molecules of NADH and FADH,, another electron carrier, are made. They leave the Krebs cycle, and the 4-carbon molecule remains. Explain During the hands-on lab, which product of the Krebs cycle caused the bromothymol blue solution to change color? Image Credits: Andrew Syred/Science Source CONTINUE YOUR EXPLORATION EA screener elo Aerobic and Anaerobic Processes in Yeast The species used in this investigation, Saccharomyces cerevisiae, like other species of yeast, is a facultative anaerobe. It can break down sugars using either aerobic or anaerobic processes, depending on the presence of oxygen. When oxygen is not present, yeast carry out ethanol fermentation. This process produces carbon dioxide and ethanol, a type of alcohol. Predict How will you know whether aerobic or anaerobic processes are occurring in the bottle? SAFETY Obtain and wear goggles for this lab. Do not eat any materials used in this lab. PROCEDURE 1. Blow up the balloon a few times to stretch it. 2. Using the funnel, pour 150 mL of warm water into the bottle. Dry the funnel. 3. Using the dry funnel, add 1 packet of yeast to the water. Swirl the mixture gently. 4. Using the funnel, add 1 tablespoon (12 g) of sugar to the yeast solution, swirl, and quickly cover the bottle with the balloon. Allow the mixture to react for 5 minutes. 5. After5 minutes have passed, use the string, marker, and ruler to measure the circumference of the balloon. 6. Inadata table, record the circumference of the balloon, along with all of your observations of what is happening in the bottle. Continue making and recording observations every 5 minutes for the next 30 minutes. 7. Dispose of waste according to your teacher's instructions. ANALYZE 1. Describe evidence, if any, that aerobic respiration took place in the bottle. 2. How does matter cycle during aerobic respiration? Explain how the reactants are rearranged to form the products. What is the source of energy, how is the energy transferred, and how is it used in the cell? » Describe evidence, if any, that fermentation took place in the bottle. 4. How does matter cycle during fermentation? Explain how the reactants are rearranged to form the products. What is the source of energy, how is the energy transferred, and how is it used in the cell? EVIDENCE FOR ENDOSYMBIOSIS ra) FIGURE 14: Yeast are single- celled organisms that belong to the group of organisms called fungi. STS a Cera Tea Termes satiety ee coe eka ree as AND CELLULAR RESPIRATION MATERIALS + active dry yeast (1 package) + balance (optional) + balloon, round + funnel + graduated cylinder * marker + ruler, metric + string, 30 cm + sugar, granulated + tablespoon (optional) + timer + water, very warm (40°C) + water bottle, plastic, 500 mL + weighing boat (optional) Oe Pea en Lesson 2 Cellular Respiration 137 EVALUATE Lesson Self-Check 138 Unit 3 Matter and Energy in Living Systems eS ea FIGURE 15: Because ethanol burns more cleanly than gasoline, Lageroeht itis added to gasoline to help reduce the emission of greenhouse gases produced by combustion enginesin cars. Like gasoline, ethanol contains energy in its chemical bonds that can be released by the process of combustion. Combustion and cellular respiration are both exothermic reactions that result in the release of energy. The energy is released when chemical bonds that store energy are broken. Combustion is a fast process that results in the production of energy in the forms of heat and light. CH,CH,OH + 0, — + — 2CO, + 3H,O + heat In contrast, cellular respiration is a slow process, with energy being released over a series of several steps. This makes energy available for use whenever cells of the body need it to carry out cellular activities. C,H,,0, +60, + + — 6CO, + 6H,O + heat + ATP Explain A scientist named Antoine Lavoisier demonstrated that cellular (5) respiration is a combustion process. Recall that car engines use a combustion reaction to release energy. Construct an explanation for how the breakdown of fuel in a car engine compares to the breakdown of fuel in your body's cells. Answer the following questions: 1. Look carefully at the equations for both combustion and cellular respiration, and compare the inputs and outputs. How can the different inputs result in the same outputs based on what you know about chemical bonds and atoms? 2. What is missing from the process of combustion that makes it an imperfect model for cellular respiration? Explain your answer. Image Credits: Houghton Mifflin Harcourt CHECKPOINTS Check Your Understanding 1. How does carbon flow between photosynthesis and cellular respiration? a. Photosynthesis produces carbon dioxide from glucose generated by the process of cellular respiration. b. Cellular respiration produces carbon dioxide from glucose generated by the process of photosynthesis. c. Photosynthesis produces carbon dioxide from ATP generated by the process of cellular respiration. d. Cellular respiration produces carbon dioxide from ATP generated by the process of photosynthesis. 2. Which of the following are the main inputs, or reactants, in cellular respiration? Select all correct answers. a. pyruvate b. glucose c. carbon dioxide d. oxygen 3. Which of the following are the main outputs, or products, of cellular respiration? Select all correct answers. a. water b. energy . oxygen d. carbon dioxide 4. Before cellular respiration, glucose must be broken down by the process of a. photosynthesis. b. glycolysis. c. electron transport. d. fermentation. 5. During which process is lactic acid formed when there is not enough oxygen present for cellular respiration to take place? a. fermentation b. glycolysis c. Calvin cycle d. Krebs cycle 6. Use the following terms to complete the statement: ATP, cellular respiration, electron transport chain, glycolysis, Krebs cycle, photosynthesis Living things require energy to grow and reproduce and to carry out different cell processes. Certain cells can capture energy from the sun through the process of. . Through a series of reactions, that energy is transferred to organisms. Through the process of the energy currency of the cell, is produced. This is a three-part process, beginning with in the cell cytoplasm and proceeding within the mitochondrion with the and, finally, the 7. How do you know that energy and matter are conserved during the process of cellular respiration? Explain. 8. Energy is transferred in several different ways during the process of cellular respiration. Give two examples of ways that energy is transferred during this process. 9. Is oxygen necessary for the production of ATP in your cells? Why or why not? 10. How are photosynthesis and cellular respiration related? MAKE YOUR OWN STUDY GUIDE In your Evidence Notebook, design a study guide that supports the main idea from this lesson: Cellular respiration is a process that breaks down food molecules to release energy to fuel cellular processes in organisms. Remember to include the following information in your study guide: + Use examples that model main ideas. + Record explanations for the phenomena you investigated. + Use evidence to support your explanations. Your support can include drawings, data, graphs, laboratory conclusions, and other evidence recorded throughout the lesson. Consider how molecules are rearranged and energy is transferred during the process of cellular respiration. Lesson 2 Cellular Respiration