Presentation on theme: "Muscle Metabolism. Goals: Describe three ways in which ATP is regenerated during muscle contraction Relate the oxygen deficit to causes of muscle fatigue."— Presentation transcript:
Goals: Describe three ways in which ATP is regenerated during muscle contraction Relate the oxygen deficit to causes of muscle fatigue
Muscle Metabolism Muscle have only a 4 to 6 second supply of ATP ATP must be continually regenerated via one of three pathways in the muscle.
Muscle Metabolism These pathways are: Direct phosphorylation of ADP by creatine phosphate Anaerobic glycolysis Aerobic respiration
Muscle Metabolism Creatine Phosphate Phosphorylation Active muscles can use all ATP within a few twitches. Creatine Phosphate is a high energy storage molecule The transfer of its high energy phosphate to ADP can provide up to 16 seconds of ATP in a muscle. Creatine phosphate is regenerated during rest. Its money for health food companies.
Muscle Metabolism Creatine Phosphate Phosphorylation This pathway is used for very quick bursts of muscle activity, such as sprinting.
Muscle Metabolism Glycolysis and Lactic Acid Formation This pathway generates ATP after the Creatine phosphate system is exhausted. Actively contracting muscles compress arteries, reducing blood flow and oxygen. This produces anaerobic conditions which produce lactic acid.
Muscle Metabolism Glycolysis and Lactic Acid Formation This pathway only produces about 5% as much ATP as aerobic respiration but does it twice as fast. This pathway extends the ATP supply up to 1 minute of vigorous activity.
Muscle Metabolism Glycolysis and Lactic Acid Formation The Big Lie by State Ed Department The build up of lactic acid leads does NOT lead to muscle soreness following exercise. It coincides with muscle fatigueIt coincides with muscle fatigue.
Muscle Metabolism Muscle Fatigue Muscle fatigue is the inability to contract even in the presence of stimuli.
Muscle Metabolism Muscle Fatigue Muscle fatigue is the inability to contract even in the presence of stimuli. It is NOT due to a lack of ATP. This would lead to contractures. This is seen with writers cramp.
Muscle Metabolism Muscle Fatigue Ionic disturbances are the most likely cause of muscle fatigue : Potassium ion lost from the muscle cells Interference of Calcium regulation
Muscle Metabolism Aerobic Respiration This pathway produces 95% of the ATP. This pathway occurs in the mitochondria and requires oxygen.
Muscle Metabolism Aerobic Respiration
Aerobic Respiration Muscle glycogen provides the major source of glucose followed by blood glucose and then fats. It provides the most ATP but is slower because of all the enzymatic steps.
Muscle Metabolism Aerobic Respiration This pathway is used for long periods of exercise such as cross county and marathon events.
Muscle Metabolism Comparisons
Muscle Fiber Type Deep down we are all turkeys
Muscle Fiber Type Deep down we are all turkeys Remember white meat/ dark meat?
Muscle Fiber Type Muscle fibers are divided into two types based on their metabolism. 1. Slow oxidative fibers (Red Meat) Aerobic Myoglobin present (Red Color) Large number of mitochondria Low glycogen content Slow rate of fatigue Good for endurance activities
Muscle Fiber Type Muscle fibers are divided into two types based on their metabolism. 2. Fast Glycolytic Fibers Anaerobic Myoglobin content is low (White Color) Glycogen content is high Fatigues quickly Few mitochondria Short term intense movements
Muscle Fiber Type A third muscle type, the Fast Oxidative Fiber has characteristics of both muscle types. These muscle can convert to the other types based on training.
Adaptation to Exercise Endurance exercising will: Increase the number of capillaries surrounding the muscle fibers (why) Increase the number of mitochondria (why) May convert some of the fast glycolytic fibers to fast oxidative fibers Increase the efficiency of the heart (why)
Adaptation to Exercise Resistance exercising will: Increase the increase the size of the muscle fibers Increase the amount of connective tissue between the fibers May convert some of the to fast oxidative fibers to fast glycolytic fibers
Adaptation to Exercise
Large bulky muscles are due to the increase size of individual muscle fibers (fast glycolytic fibers)
Adaptation to Exercise Who has the larger heart?