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14 Cards in this Set
- Front
- Back
Identify the predominant energy systems used to produce ATP during the following types of exercise:
a. Short-term, intense exercise (i.e., less than ten seconds’ duration) b. 400-meter dash |
the predominant energy system is ATP PC
a. less then 10 seconds requires anaerobic metabolic pathways ATP PC system b.comes from a combonation of ATP PC, glycolysis, and aerobic metabolism |
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oxygen debt
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the elevated post-exercise oxygen consumption (see EPOC); related to replacement of creatine phosphate, lactic acid resynthesis to glucose, and elevated body temperature, catecholamines, heart rate, breathing, etc.
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oxygen deficit
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refers to the lag in oxygen uptake at the beginning of exercise.
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gluconeogenesis
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the synthesis of glucose from amino acids, lactate, glycerol, and other short carbon-chain molecules.
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EPOC
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an acronym for "excess post-exercise oxygen consumption''; often referred to as the oxygen debt.
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Discuss several possible reasons why blood lactate begins to rise rapidly during incremental exercise.
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rising blood lactic acid levels have been considered an indication of increased anaerobic metabolism within the contracting muscle because of low levels of O2
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Metabolic Responses to Short-Term, Intense Exercise
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First 1–5 seconds of exercise
– ATP through ATP-PC system Intense exercise longer than 5 seconds – Shift to ATP production via glycolysis Events lasting longer than 45 seconds – ATP production through ATP-PC, glycolysis, and aerobic systems – 70% anaerobic/30% aerobic at 60 seconds – 50% anaerobic/50% aerobic at 2 minutes |
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failure of the mitochondrial "hydrogen shuttle system to keep pace with the rate of glycolytic production of NADH+H results in
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the conversion of pyruvic acid to lactic acid.
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possible Mechanisms to explain the lactate threshold during INCREMENTAL EXERCISE
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1 low muscle oxygen
2 Accelerated glycolysis 3. recruitment of fast twitch fibers 4 reduced rate of lactate removal |
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Briefly, explain how the respiratory exchange ratio is used to estimate which substrate is being utilized during exercise. What is meant by the term nonprotein R?
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The answer is related to the fact that fats and carbs differ in the amount of O2 used and CO2 produced
Protien generally plays a small role as a substrate during physucal activity... |
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List two factors that play a role in the regulation of carbohydrate metabolism during exercise.
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(1)recruitment of fast fibers and (2) increasing blood levels of epinephrine.
****AS the exercise increases more and more fast muscle fibers are recruited****** better equipt to metabolise carbs vs. fats. |
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High levels of epinephrine increase
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Muscle glycogen break down
carb metabolism (i.e. glycolysis increases) |
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the breakdown of muscle glycogen during exercise is regulated by what 2 seperate mechanisms?
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1. epinwphrine - cyclic AMP pathway
2. calcium -calmdulin pathway.. both pathways activate enzyme phosphorlayze(active) which degrades glycogen for entry to glycolysis. |
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the increased production of lactate inhibits
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fats metabolism by reducing the availability of fats as a substrate...
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