Honors Biology Ch. 6 Cellular Respiration Notes Opening Essay: Compare the structure and functions of slow and fast muscle fibers. Explain why some people seem to be natural sprinters. Fast Twitch Slow Twitch preferred race sprint distance sprinter 60% 40% marathoner 20% 80% ATP anaerobically aerobically production (without O2) (with O2) thicker fibers not so thick structure fewer mitochondria many mitochondria much less myoglobin lots-o-myoglobin Can switch to anaerobic resp. to % of each is notes produce ATP from determined by glucose, lactic acid genetics build-up Cells of: protists where found? muscle fungi plants animals Introduction to Cellular Respiration 6.1 Compare the processes and locations of cellular respiration and photosynthesis. Explain why it is accurate to say that life on Earth is solar-powered. Cellular Respiration: Process: breaks down glucose in the presence of oxygen to produce ATP for cellular work. Location: mitochondria Organisms: all eukaryotic cells Photosynthesis: Process: builds glucose from CO2 and H2O using the energy from the sun. Locations: chloroplasts Organisms: green plants, algae, photosynthetic protists & bacteria Life is solar-powered because the energy for all life comes from the sun and is converted from radiant energy to chemical energy by chlorophyll. 6.2 Describe and compare the processes of breathing and cellular respiration. Breathing: moving air in and out of a body to get oxygen and expel carbon dioxide. Cellular Respiration: aerobic (with O2) harvesting of energy from food molecules by cells. Mrs. Loyd cloyd@waukee.k12.ia.us Page 1 of 4 http://loydbiology.weebly.com 10/20/11 http://www.mybiology.com 6.3 Provide the overall chemical equation for cellular respiration. Compare the efficiency of this process in cells to the efficiency of a gasoline automobile engine. C6H12O6 + 6 O2 6 CO2 + 6H2O + energy 40% of the energy in 1 glucose is converted into the chemical energy of 38 ATP. 25% of the energy in gasoline is converted to kinetic energy. 6.4 Explain how the human body uses its daily supply of ATP. Minimum functions (maintenance) = 75% of calories taken in each day Voluntary Activity = varies according to activity Stages of Cellular Respiration and Fermentation 6.6 List the cellular regions where glycolysis, the citric acid cycle, and oxidative phosphorylation occur. Note whether substrate-level phosphorylation or chemiosmosis occur at each of these sites. Location Glycolysis Citric acid cycle Oxidative phosphorylation cytoplasm matrix of mitochondion across the inner membrane Substrate-Level Phoshorylation? Yes Chemiosmosis? No Yes No No Yes 6.7–6.12 Compare the reactants, products, and energy yield of the three stages of cellular respiration. Mrs. Loyd cloyd@waukee.k12.ia.us Page 2 of 4 http://loydbiology.weebly.com 10/20/11 http://www.mybiology.com Reactants 1. Glycolysis Glucose 2. Citric Acid Cycle 2 Pyruvate 2 Acetyl CoA + 2 CO2 3. Oxid. Phosph. Oxygen 12 NADH 2 FADH2 Products 2 Pyruvate 2 NADH 2 ATP (2 NADH) 6 NADH 2 FADH2 2 ATP 2 CO2 34 ATP Energy Yield in # of ATP 2 2 34 total = 38 ATP 6.13 Compare the reactants, products, and energy yield of alcohol and lactic acid fermentation. Fermentation = Anaerobic (without O2) Respiration The pathway followed is determined by the species type. Lactic Acid Fermentation (mammals) Glucose (6C) 2 Pyruvate (2 x 3C) 2 Lactate (2 x 3C) + 2 ATP Alcohol Fermentation (yeast) Glucose (6C) 2 Pyruvate (2 x 3C) 2 Ethanol (2 x 2C) + 2 CO2 + 2 ATP 6.13 Distinguish between strict anaerobes and facultative anaerobes. Strict anaerobes MUST live in the absence of oxygen. Oxygen will poison them. Facultative Anaerobes can live with oxygen or without oxygen. 6.14 Describe the evolutionary history of glycolysis. Gycolysis exists in nearly all organisms- it evolved early and was passed down Occurs in cytoplasm therefore does not require membrane-bound organelles, eukaryotes evolved 1 billion years after prokaryotes For nearly 1 billion years prokaryotes used glycolysis to make ATP because it does not need oxygen. Metabolic “heirloom” still functions in fermentation and first step in cellular respiration. Interconnections Between Molecular Breakdown and Synthesis 6.15 Explain how polysaccharides, fats, and proteins are used as fuel for cellular respiration. Explain why a gram of fat yields more ATP than a gram of starch or protein. 6.16 The process of hydrolyzing (breaking down) carbs, lipids and proteins creates the smaller molecules that fit into the process of cellular respiration at appropriate steps. Explain how nutrients are used in biosynthesis. Mrs. Loyd cloyd@waukee.k12.ia.us Page 3 of 4 http://loydbiology.weebly.com 10/20/11 http://www.mybiology.com Intermediate molecules from the breakdown of glucose can be tapped as building blocks that the cell needs. Examples: M onosaccharides polysaccharides (starch, cellulose) F atty acids and glycerol lipids A mino acids polypeptides (protein like muscle or enzymes) Mrs. Loyd cloyd@waukee.k12.ia.us Page 4 of 4 http://loydbiology.weebly.com 10/20/11 http://www.mybiology.com