1 cal = energy required to raise the temperature of 1g of water from 15 degree C to 16 degree C.
1 Cal = 1 kcal = 1000 cal
1 calorie = 4.1868 J
1mole of glucose
= 180gram
Glucose level of
180mg/dL = 10mmol/L
Carbohydrate = 4.1 kcal/g
Fat = 9.3 kcal/g
Protein = 4.1 kcal/g
* Outside body, when measured with bomb calorimeter
--> protein = 5.3 kcal/g
* Difference is due to end product being urea and other nitrogenous compounds
Respiratory quotient (RQ) = the ratio of CO2 produced to O2 consumed in steady state.
Respiratory exchange ratio (R) = the ratio of CO2 produced to O2 consumed at any given time, whether or not equilibrium has been reached.
RQ of carbohydrate = 1.0
RQ of fat = 0.7 (because extra O2 is needed for the formation of H2O)
RQ of protein = 0.82 (average value)
... is determined by the metabolic process occurring in them.
RQ of brain = 0.97 to 0.99
* Carbohydrate is the main, but not the only fuel
RQ of stomach = negative
* Negative CO2 output because of acid secretion
Isotonic muscle contraction is about 50% efficient.
Essentially all isometric contraction appears as heat and no work is done.
Basal metabolic rate is measured:
Measured indirectly.
O2 consumption is measured using oxygen-filled spirometer and a CO2 absorber.
Conversion: 4.82 kcal/L of O2 consumed
* [WG21:p284]
Correlates well with body surface area
[WG21:p284]
In providing 100 cal worth of energy, metabolic rate increase by:
The most important - adenosine triphosphate (ATP)
Others include:
After picking up hydrogen
##20050509-01
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Created | 20050514 |