Interest Grabber Section 9-1 Feel the Burn Do you like to run, bike, or swim? These all are good ways to exercise. When you exercise, your body uses oxygen to get energy from glucose, a six-carbon sugar. 1. How does your body feel at the start of exercise, such as a long, slow run? How do you feel 1 minute into the run; 10 minutes into the run? 2. What do you think is happening in your cells to cause the changes in how you feel? 3. Think about running as fast as you can for 100 meters. Could you keep up this pace for a much longer distance? Explain your answer. Go to Section: Interest Grabber Section 9-1 Feel the Burn 1. How does your body feel at the start of exercise, such as a long, slow run? How do you feel 1 minute into the run; 10 minutes into the run? Students may answer that they feel no fatigue at the start of a run; however, after 1 minute and more so after 10 minutes, they are breathing hard, their heart rate has increased significantly, and their muscles may hurt. Go to Section: Interest Grabber Section 9-1 Feel the Burn 2. What do you think is happening in your cells to cause the changes in how you feel? Students may say that the increase in heart rate and breathing rate are a response that gets extra oxygen to the cells. The pain may be attributed to the cells becoming fatigued. Go to Section: Interest Grabber Section 9-1 Feel the Burn 3. Think about running as fast as you can for 100 meters. Could you keep up this pace for a much longer distance? Explain your answer. Students may know that very high levels of performance can be sustained only very briefly even among the best of athletes. Students may say that the body runs out of readily available energy, food, or oxygen, or that the body builds up too many waste products in the cells. Go to Section: Section Outline Section 9-1 9–1 Chemical Pathways A. Chemical Energy and Food B. Overview of Cellular Respiration C. Glycolysis 1.ATP Production 2.NADH Production D. Fermentation 1.Alcoholic Fermentation 2.Lactic Acid Fermentation Go to Section: Each of our bodies has a different way to let us know when we are hungry. Food serves as a source of raw materials from which our bodies form new cells. __________________________. 3811 calories of 1 gram of sugar releases _______ heat energy. A calorie is the amount of energy needed to 1 gram of water raise the temperature of ______________ ___________________. 1 degree Celsius. When we consume food, our bodies breakdown food__________________________________. to release energy and build new cells The breakdown of food begins with the process glycolysis called _______________________. Video 2 Glycolysis Click the image to play the video segment. Video Chapter 9B.mpg Glycolysis comes from the Greek word glukus meaning “sweet” and the Latin ____________ word lysis means “dissolving or decomposing” ______________________. 1st step of glycolysis •2 ATPS are needed to activate glucose. 2nd step Splitting of Glucose •Glucose is split into 2 3-carbon compounds. See animation of glycolysis 3rd Step of Glycolysis – Energy Generation • 2 NAD+ are reduced. At the same time, a phosphate group is added to each 3 carbon molecule. •2 ATPs replace those required for activation. •A net of 2 ATPs per glucose are produced in glycolysis. Glycolysis is the process in which one molecule of glucose is broken in half producing two pyruvic acid / pyruvate molecules of ______________________. Produces 4 ATP molecules. Glycolysis 2 ATP molecules were used in producing the 4 ATP molecules Net gain of 2 ATP overall • GLYCOLYSIS • Happens in ______________ CYTOPLASM of cell • Four electrons are passed to an electron carrier called _______________ NAD+ • NAD+ accepts electrons to make __________ NADH NAD+ is nicotinamide adenine • _______ dinucleotide. HIGH ENERGY ELECTRONS require a special carrier, too • • • • ____________ NAD+ is one of the carriers that cells use to transport high energy electrons. + ________ + _____ NAD 2 e + _____ H+ → ____________ NAD+ _______= nicotinamide adenine dinucleotide Figure 9–2 Cellular Respiration: An Overview Section 9-1 Mitochondrion Electrons carried in NADH Pyruvic acid Glucose Glycolysis Krebs Cycle Electrons carried in NADH and FADH2 Electron Transport Chain Mitochondrion Cytoplasm Go to Section: Figure 9–3 Glycolysis Section 9-1 Glucose 2 Pyruvic acid To the electron transport chain Go to Section: Figure 9–3 Glycolysis Section 9-1 Glucose 2 Pyruvic acid To the electron transport chain Go to Section: Figure 9–3 Glycolysis Section 9-1 Glucose 2 Pyruvic acid To the electron transport chain Go to Section: it is needed in •NADH holds the electron until ___________________ ______________________. following events small • The energy yield from glycolysis is __________. •The process is so fast that cells can produce just a few milliseconds thousands of ATP molecules in __________________. not require oxygen •Besides speed, glycolysis does _________________. •Without NAD+, the cell cannot keep glycolysis going, ATP production stops and ______________________________. Following Glycolysis when oxygen is absent: If oxygen is not present, a cell begins with glycolysis and continues with a different pathway called fermentation. There are two types of fermentation: Alcoholic Fermentation •________________ Lactic Acid Fermentation •________________ NAD+ During fermentation NADH converts to _________. anaerobic This is an ______________ process. Alcoholic Fermentation Pyruvic acid + NADH → alcohol + carbon dioxide + NAD+ Used in bread production (leavened bread) uses yeast to raise the bread. Yeast uses sugar and gives off carbon dioxide. The alcohol generated cooks out of the bread when baking. Figure 9–4 Lactic Acid Fermentation Section 9-1 Glucose Go to Section: Pyruvic acid Lactic acid Figure 9–4 Lactic Acid Fermentation Section 9-1 Glucose Go to Section: Pyruvic acid Lactic acid Figure 9–4 Lactic Acid Fermentation Section 9-1 Glucose Go to Section: Pyruvic acid Lactic acid Lactic Acid Fermentation Pryuvic acid + NADH → lactic acid + NAD+ When you exercise vigorously by running/swimming, your muscle cells need oxygen. When there is not enough oxygen, your body can’t produce all the ATP that it needs. Your muscles begin to generate ATP by lactic acid fermentation. This buildup causes a painful burning sensation. This is why muscles feel sore or you get a side ache. You need to breathe to reverse the lactic acid fermentation to cellular respiration. Lactic Acid Fermentation Unicellular organisms produce lactic acid as a waste product during fermentation. Prokaryotes (good bacteria) are used in the production of a wide variety of foods and beverages such as cheese, yogurt, buttermilk, sour cream, pickles, sauerkraut, and kimchi. All of the above foods are produced using lactic acid fermentation. Chemical Pathways Section 9-1 Glucose Glycolysis Krebs cycle Fermentation (without oxygen) Go to Section: Electron transport Alcohol or lactic acid SOUTH DAKOTA SCIENCE STANDARDS • Chapter 9 – Cellular Respiration: • The students will be able to • describe the process of cellular respiration (9-12.L.1.1) • identify the components of glycolysis (9-12.L.1.1) • compare the processes of alcoholic and pyruvic acid fermentations (9-12.L.1.1) • analyze chemical reaction and chemical processes involved in the Krebs Cycle (9-12.L.1.1) • explain the mitochondrial role in the ATP-ADP cycle (9-12.L.1.1) • Assess the role of enzymes in plant reactions (LAB) SOUTH DAKOTA CORE SCIENCE STANDARDS LIFE SCIENCE: Indicator 1: Understand the fundamental structures, functions, classifications, and mechanisms found in living things • 9-12.L.1.1. Students are able to relate cellular functions and processes to specialized structures within cells. • Photosynthesis and respiration • ATP-ADP energy cycle Role of enzymes Mitochondria Chloroplasts Core High School Life Science Performance Descriptors High school students performing at the ADVANCED level: analyze chemical reaction and chemical processes involved in the Calvin Cycle and Krebs Cycle; predict the function of a given structure; High school students performing at the PROFICIENT level: describe and give examples of chemical reactions required to sustain life (…role of enzymes) describe and give examples of chemical reactions required to sustain life (hydrolysis, dehydration synthesis, photosynthesis, cellular respiration, ADP/ATP, role of enzymes); describe the relationship between structure and function High school students performing at the BASIC level name chemical reactions required to sustain life (… role of enzymes) name chemical reactions required to sustain life (hydrolysis, dehydration synthesis, photosynthesis, cellular respiration, ADP/ATP, role of enzymes); recognize that different structures perform different functions; SOUTH DAKOTA ADVANCED SCIENCE STANDARDS LIFE SCIENCE: Indicator 1: Understand the fundamental structures, functions, classifications, and mechanisms found in living things. • 9-12.L.1.1A. Students are able to explain the physical and chemical processes of photosynthesis and cell respiration and their importance to plant and animal life. (SYNTHESIS) • Examples: Krebs Cycle