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11 Cards in this Set
- Front
- Back
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what is energy transduction?
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converting chemical to other forms of energy
cell work includes mechanical, chemical, osmotic and electrical forms |
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what are the three major stages of energy transduction?
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photosynthesis (delta G is positive), cell respiration (delta G is negative), cell work
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what do calorimeters do?
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measure heat directly and indirectly - by estimating metabolic rate based on CO2 production and O2 consumption
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how does a bomb calorimeter work?
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used to ignite and burn foodstuffs in oxygen under pressure
can determine heat of combustion of certain foods |
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describe indirect calorimetry
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during exercise some of the energy liberated in the body appears as physical work outside, measured by devices like ergometers and treadmills
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how do you calculate RER?
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CO2 produced/ O2 consumed
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what happens to RQ during exercise?
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it will approach 1.0 during hard exercise and may be somewhat lower during prolonged exercise indicating less carbohydrate and more lipid use, training improves ability to use fat as a fuel during prolonged exercise
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what are the limits of using RER during exercise using indirect calorimetry?
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not only respiration supplying energy for ATP
cellular events not immediately expired in air CO2 is stored in cells to maintain sodium bicarbonate as a buffer to lactic acid, and extra is produced during hard exercise, therefore RER=RQ |
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what are other limits posed by exercise in measuring RER?
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If RER=1.0 than we know CHO is used but we don't know specific fuel (PA, LA, glucose, glycogen)
urine production decreases and nitrogen is lost in sweat during exercise thus N excretion during exercise is difficult EPOC |
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what is body efficiency?
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the respiratory response to graded submaximal exercise at specific external work rates
the fraction of energy liberated that appears as external work is calculated |
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how do you measure body efficiency during exercise?
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change in work output/ change in VO2
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