Lab Exam 1- Lab 2 Flashcards
1 MET =
3.5 mL/kg/min
1 L O2 = ___ kcal
5 kcal
aerobic metabolism uses what 3 substrates and for what
carbs, proteins, and fats for ATP production
all energy transformations that occur in the human body:
cellular
chemical
mechanical
anabolic reactions
require energy input
associated energy cost of TEF on TDEE
10%
ATP is made of
cell work + heat
BMR accounts for what % of TDEE
60-70%
BMR is responsible for
energy utilized to sustain all cellular, chemical, and mechanical work at rest
calorie
the heat required to raise the temperature of 1 gram of water 1 degree celcius
catabolic reactions
yield energy
direct calorimetry
quantifies the heat produced by a resting or exercising animal
direct calorimetry measures
heat loss
do we need to measure O2 and CO2 fractions in inspired air
no always constant
during exercise is all or some of heat generated going towards work
only part of energy transformed by metabolic pathways directly does work
EAT
exercise activity thermogenesis
accounts for EE
associated with sport specific exercising
energy balance occurs when
energy intake = energy expenditure
* however this is a static equation because humans are dynamic
energy lost
the portion of energy released that does not contribute towards work (heat)
allows us to calculate mechanical efficiency
expressing a gas volume in STPD makes it possible to compare and evaluate VO2 values calculated at
different altitudes, temperature, and humidity
FiCO2
0.0003
FiO2
0.2093
gross efficiency varies with
work rate
cadence
fiber type
contraction type
Gross Mechanical Efficiency (ME)
ratio of mechanical power (mechanical work rate) to metabolic power
how are we measuring energy expenditure in this lab
by measuring VO2
how do you measure expired and inspired O2
douglas bag technique
how does a calorimeter work
a subject is placed in a chamber surrounded by an insulated water jacket
thermometers in the water jacket measure temp change in the water
using heat of water and mass of water,, the heat loss (C) from the subject to the walls of the chamber is calculated
how does douglas bag technique work
a subject breathes through a mouthpiece attached to two way valve (Daniel’s Valve) that allows entry of atmospheric air to be inspired and removes expired air through the other side
volume of air expired (Ve) is collected into plastic Douglas bags and analyzed for concentrations of fractional expired O2 (FeO2) and CO2 (FeCO2) via gas anyalysis machines (PARVO)
how is metabolic rate measured
via direct or indirect calorimetry
how is Ve measured
via a volumeter
how many kcal per LO2 for combustion of fat
4.851 kcal*LO2-1
how many kcal per LO2 for combustion of protein
4.5 kcal*LO2-1
how many kcal yielded per LO2 for carbs
5.189 kcal*LO2-1
how many kcal yielded per LO2 in combustion of a mixed diet
4.98 kcal*LO2-1
how many kcal yielded per LO2 in combustion of a starving individual
4.851 kcal*LO2-1
how are calories quantified in this lab
kcal
what unit does the calorimeter measure heat
in calories
increased work rate requires
increased rate of EE
indirect calorimetry is used
in aerobic metabolism in order to determine metabolic rate from O2 uptake
indirect calorimetry measures
O2 consumption only from oxidative pathways
is the human machine 100% efficient
NO some energy is lost as heat
key characteristics of VE
saturated with water vapor and is at an ambient temp and pressure (ATPS) making comparisons under different environmental conditions difficult
main accomplishment of DIRECT calorimetry
provide a DIRECT measurement of all heat production in the body including both aerobic and anaerobic metabolism
main component of TDEE
basal metabolic rate (BMR)
metabolic power
rate of energy expenditure required to maintain this specific mechanical work rate)
metabolism
reflects all chemical and cellular reactions, as well as mechanical work that occurs in living cells
NEAT
non-exercise activity thermogenesis
energy cost of all other forms of physical activity
FiN2
0.7904
normal values for ME in humans
0-30% depending on intensity, exercise type, muscle fiber type, etc
open circuit spirometry
determines the rate of O2 uptake (VO2) by subtracting the inspired O2 (VIO2) minus expired O2 (VeO2)
rate of heat loss is measured as
a reflection of the metabolic rate of an organism
rate of heat production is proportional to
metabolic rate
RMR is approximately
3.5 mL/kg/min
2nd law of thermodynamics
2 isolated systems that differ in any way will equalize if given the opportunity
STPD stands for
standard temperature and pressure, dry
TDA
total daily activity
calculated by EAT + NEAT
TDAT components
total daily activity thermogenesis
made of energy cost of exercise activity thermogenesis (EAT) and non-exercise activity thermogenesis (NEAT)
TDEE
total daily EE
TEF
thermic effect of food
energy cost for the digestion of food and absorption of nutrients
third component of TDEE
TDAT or total activity thermogenesis
VO2 is
the RATE of O2 consumption
VO2 is proportional to
energy expenditure (EE) during predominantly aerobic tasks
what 3 things are we measuring during the procedure
resting VO2 sitting on a chair for 8 min
VO2 on a treadmill at 2mph w 2% incline for 8 min
VO2 on cycle ergometer to produce a work rate of 60 watts for women and 100 watts for men for 8 min
what do humans need to do work
energy
what do we need to understand to measure metabolic rates in living organisms
2nd law of thermodynamics
what do you need to estimate ME
quantify the amount of mechanical work done and corresponding energy expenditure during exericse
what else takes a % of TDEE
TEF or thermic effect of food
what factors do you need to take into account when determining rate of O2 consumed
Ve (volume of expired air) or pulmonary ventilation (L/min)
FeO2 and FeCO2
barometric pressure and temperature
what happens when humans transform energy to do work
heat is released
ATPS
ambient temperature and pressure
what is important when performing indirect calorimetry
closely measure the amount of O2 consumed and CO2 produced by the organism by using a closed or open circuit spirometry
what is released as a product of all metabolic reactions
heat
what is the caloric expenditure of exercise
5kcal*LO2-1
what is the device used to measure heat production
calorimeter
what is the specific heat of water
1caldeg-1g-1
what must you do to all Ve calculations as a result of different environmental conditions
all Ve collected in douglas bag are corrected to dry gas at standard temperature and pressure (STPD) using a correction factor based upon ambient conditions)
what two variables are required for standardization of different environmental conditions
room temperature
Barometric pressure (Pb)
what type of calorimetry are we doing in the lab
indirect open circuit
what unit is used to measure the mass of water in the calorimeter
g
when is Ve measured (expired minute ventilation)
as it comes out of the mouth from the lungs
why is inspired minute ventilation (VI) not measured but calculated
based on the assumption that N is not exchanged across the lung
VIN2 (inspired)= VEN2 (expired)
how to calculate gross efficiency
mechanical power/metabolic power
factors the affect BMR
fat free mass
Age
Sex (lower in females)
body fatness
genetics
caloric restriction/starvation
exercise
what happens to BMR with an increase in body fat
BMR decreases 0.01 kcal/min with every 1% increase in body fat
BMR is proportional to
FFM
fat free mass
the MET is a unit that represents
multiples of resting metabolic rate
what must be measured during open circuit spirometry
Ve, FeCO2, FeO2
