LESSON 7 - energy expenditure Flashcards
FILL IN THE BLANK
all metabolic processes ultimately result in _____ production
heat
what are the two outcomes of substrate metabolism efficiency ?
ATP and heat
what percentage of substrate energy is ATP ?
40%
what percentage of substrate energy is heat ?
60%
what essentially defines metabolic rate ?
heat
FILL IN THE BLANK
_______ production rate from cells, tissues, and the whole body operationally defines metabolic rate
heat
when does heat production increase ?
with energy production
what represents the basic unit of heat measurement ?
calorie (kcal)
what refers to measurement of heat transfer ?
calorimetry
what is a kilocalorie ?
unit of energy
what is the amount of heat energy needed to raise the temperature of 1 kg of water by 1 degree Celsius ?
kilocalorie
1 kcal =
4.184 kilojoules
how do we measure a kilocalorie ?
measured with bomb calorimeter
is oxygen highly flammable ?
yes
what will give us an indicator of energy expenditure ?
how much heat is released
what occurs within the sealed thick walled reaction chamber ?
energy is transferred into the water so the surrounding water absorbs the heat from the combustion
1g = how many calories ?
4 calories
1g = how many proteins ?
4 calories
1g = how many fats ?
9 calories
what are the two ways we quantify human energy expenditure ?
indirect and direct calorimetry
what is indirect calorimetry ?
- O2 uptake and CO2 production
- how heavy their breathing
what is direct calorimetry ?
- heat
- direct measure of how hard someone is working
what type of calorimetry measures heat production ?
direct calorimetry
what type of calorimetry measures oxygen consumption and carbon dioxide production ?
indirect calorimetry
what are the three indirect heat measurements ?
- O2 uptake
- CO2 production
- N2 balance
what is a human calorimeter ?
direct measure of heat production and thus kcal expended
is a human calorimeter indirect or direct ?
direct
does measuring a persons rate of oxygen uptake provide an indirect or direct (but accurate) estimate of energy expenditure ?
indirect
what are the two types of indirect calorimetry ?
closed-circuit and open-circuit spirometry
is it indirect or direct which measures the uptake/consumption of oxygen from the product side of the catabolic reaction ?
indirect
what is closed-circuit spirometry ?
how much volume of O2 has gone down
rate of volume reduction =
VO2 in L/min