Chapter 9 Study Guide Answers 1 Can cells like skeletal muscle cells store a large quantity of ATP molecules No skeletal muscle cells cannot store large amounts of ATP Available ATP is used up within 4 6 seconds 2 Is creatine phosphate found in body cells other than skeletal muscle fibers Creatine phosphate is primarily found in skeletal muscle fibers not in significant amounts in other body cells 3 Name the enzyme that catalyzes the breakdown of creatine phosphate The enzyme is creatine kinase 4 Describe how ATP forms from creatine phosphate How many ATP molecules are produced from the breakdown of one molecule of creatine phosphate Creatine phosphate donates a phosphate group to ADP to form ATP One ATP molecule is produced from the breakdown of one creatine phosphate 5 Explain why the breakdown of creatine phosphate and formation of ATP are considered to be coupled reactions These reactions are coupled because the breakdown of creatine phosphate directly provides the energy needed to form ATP 6 Define anaerobic Classify glycolysis as aerobic or anaerobic Anaerobic means without oxygen Glycolysis is an anaerobic process 7 Identify where in the cell glycolysis takes place Glycolysis takes place in the cytoplasm sarcoplasm of the cell 8 Glycolysis refers to the breakdown of glucose into 2 molecules of pyruvic acid 9 Give the number of ATP molecules that result from glycolysis beginning with one molecule of glucose Glycolysis produces 2 ATP molecules per one glucose molecule 10 Define glycogen Glycogen is stored glucose found in cells especially liver and muscle cells 11 The main source of glucose for glycolysis in skeletal muscle fibers is muscle fibers 12 Name two organs that can store glucose as glycogen The liver and skeletal muscles store glucose as glycogen 13 Describe two conditions that may cause the amount of oxygen in skeletal muscle to decrease High intensity activity and compressed blood vessels can reduce oxygen availability 14 If no oxygen is present in the cell pyruvic acid is converted to What is the result of build up of this substance in skeletal muscles Pyruvic acid is converted into lactic acid Build up causes muscle soreness 15 Lactic acid enters the bloodstream and is transported to the What does this organ do with the lactic acid Lactic acid enters the bloodstream and is taken to the liver The liver converts it into pyruvic acid glucose or glycogen 16 If lactic acid is not transported to the organ listed in 15 above it s excreted in urine 17 Give two terms for the catabolism of glucose in the presence of oxygen Cellular respiration and aerobic respiration 18 In which cellular organelle does oxidative phosphorylation take place Oxidative phosphorylation occurs in the mitochondria 19 Define aerobic Classify oxidative phosphorylation as anaerobic or aerobic Aerobic means with oxygen Oxidative phosphorylation is aerobic 20 List all the products of oxidative phosphorylation Products include ATP up to 32 per glucose CO2 and H2O 21 Define muscle fatigue Muscle fatigue is the inability of muscle to contract despite stimulation 22 Describe possible causes of muscle fatigue Causes include ionic imbalances increased phosphate decreased ATP and increased magnesium 23 List three types of skeletal muscle fibers Identify each muscle fiber s main method of producing ATP Slow oxidative fast oxidative glycolytic and fast glycolytic ATP production oxidative phosphorylation both glycolysis respectively 24 List characteristics of each type of skeletal muscle fiber Slow oxidative fatigue slowly red many mitochondria Fast oxidative glycolytic intermediate fatigue red pink many mitochondria Fast glycolytic fatigue quickly white few mitochondria 25 Of the three types of skeletal muscle fibers listed in 23 above which contracts slowly Which contract fast Slow oxidative fibers contract slowly Fast oxidative glycolytic and fast glycolytic fibers contract fast 26 Relate myosin ATPase activity to speed of muscle contraction Of the three types of muscle fibers listed in 23 above which contains myosin ATPase that breaks down ATP quickly Which contains myosin ATPase that breaks down ATP slowly Myosin ATPase determines contraction speed Fast fibers have fast ATPase slow oxidative has slow ATPase 27 Myoglobin binds with and stores Which method of producing ATP requires oxygen glycolysis or oxidative phosphorylation Myoglobin stores oxygen Oxidative phosphorylation requires oxygen 28 Of the three types of muscle fibers listed in 23 above which contains the most myoglobin The least Relate this answer to your answer to 26 above Slow oxidative fibers have the most myoglobin fast glycolytic have the least Myoglobin content matches the oxygen need 29 Which of three types of muscle fibers listed in 23 utilize glycogen for production of ATP Which utilizes glucose transported via the bloodstream for production of ATP Fast glycolytic fibers use glycogen Slow oxidative use blood glucose 30 What causes skeletal muscle fibers to be red Myoglobin causes the red color 31 Explain why slow oxidative fibers are red and fast glycolytic fibers are white Slow oxidative fibers are red due to high myoglobin fast glycolytic are white due to low myoglobin 32 Explain why slow oxidative fibers and fast oxidative glycolytic fibers have a lot of mitochondria capillaries while fast glycolytic fibers don t Slow and fast oxidative fibers need more oxygen for ATP so they have more mitochondria and capillaries 33 Compare the diameters of the three types of skeletal muscle fibers Slow oxidative small fast oxidative glycolytic large fast glycolytic intermediate 34 Describe the activities that the three types of skeletal muscle fibers are best suited for Slow oxidative endurance fast oxidative glycolytic sprinting walking fast glycolytic intense short term activity 35 In general which type of skeletal muscle movement would use ATP produced by creatine phosphate breakdown Short term high intensity movements use ATP from creatine phosphate 36 Define muscle tension load motor unit Muscle tension force exerted load opposing force motor unit motor neuron and muscle fibers it stimulates 37 Differentiate between small and large motor units and describe the general type of muscle movement provided by each Small motor units fine control large motor units gross movements 38 Define muscle twitch myogram Muscle twitch single contraction Myogram recording of a twitch 39 List the phases of a muscle twitch Explain why there is no change in