Cellular Respiration PDF

Lesson 3 Cellular Respiration  Focus Question How does your body get energy from eating lettuce?  Learning Objective: To be able to explain the process of cellular respiration, including its stages, the role of oxygen, and its comparison to photosynthesis, using models and...

Lesson 3 Cellular Respiration  Focus Question How does your body get energy from eating lettuce?  Learning Objective: To be able to explain the process of cellular respiration, including its stages, the role of oxygen, and its comparison to photosynthesis, using models and diagrams to visualize energy flow and chemical equations.  New Vocabulary anaerobic process glycolysis aerobic respiration Krebs cycle aerobic process fermentation  Review Vocabulary cyanobacterium: the type of bacterium that is a photosynthetic autotroph  Let’s meditate! Breathing? Respiration? Aerobic respiration? Anaerobic respiration?  THINK Why is breathing vital to life? Supplies oxygen needed for cellular respiration and release of energy. How is the air you breathe in different from the air you breathe out? more oxygen, less carbon dioxide Plants use photosynthesis to make their own food. Animals eat other organisms as food. But food is not a direct source of energy. Instead, plants, animals, and other eukaryotes break down molecules from food to produce ATP. Cellular respiration releases chemical energy from sugars and other carbon based molecules to make ATP when oxygen is present. Cellular respiration is an aerobic (air-OH-bihk) process, meaning that it needs oxygen to take place. Cellular respiration takes place in mitochondria, which are often called the cell’s “powerhouses” because they make most of a cell’s ATP. A mitochondrion cannot directly make ATP from food. First, foods are broken down into smaller molecules such as glucose. Then, glucose is broken down, as shown below. Glycolysis (gly-KAHL-uh-sihs) splits glucose into two three-carbon molecules and makes two molecules of ATP. Glycolysis takes place in a cell’s cytoplasm and does not need oxygen. Glycolysis is an anaerobic process because it does not need oxygen to take place. However, glycolysis is necessary for cellular respiration. The products of glycolysis are broken down in mitochondria to make many more ATP.  Where is this ATP produced in a cell? MITOCHONDRIA Explain what is the function of cellular respiration? Cellular respiration breaks down sugars to produce ATP for cell activities. Photosynthesis and cellular respiration are not true opposites, but you can think about them in that way. For example, chloroplasts absorb energy from sunlight and build sugars. Mitochondria release chemical energy to make ATP. The chemical equation of cellular respiration is also basically the reverse of photosynthesis. But the structures of chloroplasts and mitochondria are similar. A mitochondrion is surrounded by a membrane. It has two parts that are involved in cellular respiration: the matrix and the inner mitochondrial membrane. In mitochondria, cellular respiration takes place in two main stages: Krebs cycle and electron transport. Organisms that Use Cellular Respiration - Video & Lesson Transcript | Study.com  Draw and label the parts of a mitochondrion. Almost there: Explain where organisms get the energy they need for life process. On track: Define cellular respiration. Ready for more: Compare photosynthesis and cellular respiration. Extended work: https://www.youtube.com/watch?v=eJ9Zjc-jdys  Learning Objective: To be able to explain the process of cellular respiration, including its stages, the role of oxygen, and its comparison to photosynthesis, using models and diagrams to visualize energy flow and chemical equations.  Warm up How are combustion and cellular respiration alike? How are they different? Both are chemical reactions that use oxygen to release energy; both produce heat. Cellular respiration releases energy slowly, with many reactions, while combustion releases energy as heat and light all at once.  Correlation between a campfire and Cellular Respiration Analyzing a campfire can clarify your understanding of cellular respiration. –A campfire breaks chemical bonds in wood, releasing stored energy as light and heat –Cellular respiration breaks chemical bonds in glucose, releasing stored energy and transferring some to 38 ATP; some energy is lost as heat.  Overview of Cellular Respiration Cellular respiration occurs in mitochondria.  Overview of Cellular Respiration Cellular respiration occurs in two main parts: glycolysis and aerobic respiration. Glycolysis is an anaerobic process, meaning it does not require oxygen. Aerobic respiration involves the Krebs cycle and electron transport. Aerobic processes require oxygen.  Glycolysis Glucose is broken down in the cytoplasm through the process of glycolysis. Two molecules of ATP and two molecules of NADH are formed for each molecule of glucose that is broken down.  Krebs Cycle Preparatory Reaction Pyruvate reacts with coenzyme A (CoA) to form acetyl CoA and carbon dioxide. NAD+ is converted to NADH. Acetyl CoA moves into the mitochondrial matrix.  Krebs Cycle Steps of the Krebs Cycle Acetyl CoA combines with a 4-carbon compound to form citric acid. Citric acid is broken down, releasing two molecules of carbon dioxide and generating one ATP, three NADH, and one FADH2. Finally, acetyl CoA and citric acid are generated, and the cycle continues.  Krebs Cycle The net yield from the Krebs cycle is six carbon dioxide molecules, two ATP, eight NADH, and two FADH2.  THINK How do you know that glycolysis releases energy? Two ATP molecules (net) and two NADH molecules are produced.  SUMMARIZE How does glycolysis result in a net gain of two ATP molecules? Glycolysis makes four ATP molecules but two ATP are used to split the glucose molecule, yielding a net gain of two ATP.  THINK Where does the Krebs cycle take place? Mitochondrion matrix  THINK How many membranes does a pyruvate molecule cross? Two: outer and inner membranes of mitochondrion  Krebs Cycle Electron Transport Electron transport occurs along the mitochondrial matrix.