Week 08 - Energy Expenditure Flashcards
(47 cards)
Work =
Work = Force x distance
Power =
Power = work / time
1 L O2 = ___ kcals if 100% CHO
5.1 kcals (CHO)
1 L O2 = ____ kcals if 100% fat
4.7 kcals (fat)
Complete oxidation of 1 gram of fat requires ____ oxygen than the amount of CO2 produced
more
Complete oxidation of 1 gram of CHO requires _____ oxygen as the amount of CO2 it produces
the same amount
Exergonic =
process that release (frees up) energy into its surroundings
Endergonic =
stores or absorbs energy
Enzymes =
protein that catalyses a biological reaction
Enzymes & co-enzymes function as (3):
- biological catalysts
- couplers
- regulators of metabolism
Factors influencing enzyme function (3):
- pH
- Temperature
- Availability of substrate and enzyme
Does anaerobic energy system require O2?
No
Does aerobic energy system require O2?
Yes
Where does anaerobic system occur?
sarcoplasm
Where does aerobic system occur?
mitochondria
2 disadvantages of the phosphocreatine system (PCr)
- limited capacity
- Total amount of energy available is small
Adenylate kinase in important during _____ ????
High intensity exercise
Foods contain energy in… (3)?
- CHO
- Protein
- fat
1 calorie expresses the quantity of energy needed to raise ….?
1 ml of water by 1 C
1 joule expresses the quantity of energy needed to move…?
1g at a velocity of 1 m/s
Rate of O2 consumed is directly related to …?
Rate of energy produced
Closed circuit spirometry describes…
breathe through mouthpiece, CO2 gets trapped, O2 consumed decrease O2 in spirometer, Change in volume is measured and O2 uptake is used to calculate EE
Open circuit spirometry describes….
- measured breathing ambient air
- EE is measured from O2 and CO2 content of inspired and expired air
Indirect calorimetry…?
- Douglas bag
- Breath-by-breath systems: measure volume at mouth piece, small gas sample is collected at every expiration
