Midterm 4 Heat generation and energy balance Flashcards
What kind of process is catabolism?
an endogenic process while energy is released
a building process
proteins are formed from amino acids
polysaccharides are formed from fats
An endogenic process while energy is released
Burning fat or glucose as energy source
What kind of process is anabolism?
an endogenic process while energy is released
a building process which needs energy for synthesis
a chemical reaction while compounds are transformed without energetic change
amino acids are formed from proteins
a building process which needs energy for synthesis
For example using proteins to build muscles or fat on the body
Who introduced the law of conservation of energy?
H. A. Krebs
W. Harvey
A. L. Lavoisier and P. S. Laplace.
H. Starling
Lavoisier and Laplace
Which hormone is important during long term adaptation to the changes in the environmental temperature?
noepinephrine
thyroid hormones
growth hormone
epinephrin
Thyroid hormones
What is the most common reason for the increase of the metabolic rate?
milk production
nutrition of the fetus
increase of muscle work
sympathetic tone
Increase of muscle work
Which growing animal has the best feed utilization?
lactating cow
pig
beef cattle
laying hen
Laying hen
What is true for vital protein digestion?
the undigested defecated protein is subtracted from the fodder’s protein content
the undigested defecated protein and the endogenous nitrogen in the faeces are subtracted from the fodder’s protein content
it is independent of the quantity of endogenous nitrogen
it is the exact measurent of protein digestibility
The undigested defecated protein and the endogenous nitrogen in the faeces are subtracted from the fodder’s protein content
How can the net protein utilization be measured?
during its measurement it is unnecessary to starve the animal
the endogenous nitrogen content of the faeces is subtracted from the virtual protein digestion
the urine nitrogen is subtracted from the ingested protein
the undigested defecated protein is subtracted from the fodder’s protein content
The urine nitrogen is subtracted from the ingested protein
What information does the biological utilization give?
it states the reason of improper protein utilization
it gives information on how much is the real protein digestion
it gives information on how much of the given fodder is absorbed in the gut
it gives information on how much of the degraded and absorbed protein can take part the synthesis of the organism’s new proteins
it gives information on how much of the degraded and absorbed protein can take part the synthesis of the organism’s new proteins
How can energy, which is released during metabolism, be calculated?
Energy released = stored energy - heat - work
Energy released = work + stored energy - heat
Energy released = (internal work - external work) + stored energy + heat
Energy released = stored energy + heat + work
Energy released = stored energy + heat + work
What is the definition of one calorie?
1 calorie is defined as the amount of energy required to raise the temperature of one gram of water from 14.5 °C to 15.5 °C
1 calorie is defined as the amount of energy required to raise the temperature of one gram of water by one degree Celsius
1 calorie is defined as the amount of energy released by combustion of 1 g of foodstuff
Calorie is a general unit of measurement for heat, work, and energy
1 calorie is defined as the amount of energy required to raise the temperature of one gram of water from 14.5 °C to 15.5 °C
Which of the measuring units below is associated the quantity of heat?
Calorie
Joule
Kcal
°C
Joule
What is the combustion heat for nutrients?
the amount of heat produced by burning of 1 g protein
the amount of heat produced by burning of 1 g foodstuff
the amount of heat produced by burning of 1 g particular nutrient
the difference between the energy released in the bomb calorimeter and the in the body
The amount of heat produced by burning of 1g particular nutrient
How can you determine the total heat energy in the foodstuff?
By direct calorimetry
By indirect calorimetry
By calculation
By bomb calorimeter
By bomb calorimeter
What is the “Hess law”?
The amount of energy released by oxidation is independent of the intermediate steps
Oxidation of proteins releases the same amount energy in the body and in the bomb calorimeter
The oxidation has the same intermediate steps in the body and in the bomb calorimeter
The combustion heat of different nutrients depends on the intermediate steps
The combustion heat of different nutrients depends on the intermediate steps
What is gross energy (GE)?
The difference of metabolizable energy and heat produced in the body
The energy content of the foodstuff measure in bomb calorimeter
GE = combustion heat - energy in faeces
GE = combustion heat - energy in faeces - energy in urine
The energy content of the foodstuff measure in the bomb calorimeter
What is the real protein digestion?
the undigested defecated protein is subtracted from the protein content of the feed
the endogenous nitrogen content in the faeces is subtracted from the virtual protein digestion
during its determination it is unnecessary to starve the animal
the endogenous nitrogen content of the faeces and the urine nitrogen content are subtracted from the virtual protein digestion
the endogenous nitrogen content in the faeces is subtracted from the virtual protein digestion
What is the digestible energy (DE)?
The energy content of the foodstuff measured in bomb calorimeter
DE = combustion heat - energy in faeces - energy in urine
DE = combustion heat - energy in faeces
The difference of metabolizable energy and heat produced in the body
DE = combustion heat - energy in faeces
What is the metabolizable energy (ME)?
ME = net energy - energy in urine
The energy content of the foodstuff measure in bomb calorimeter
ME = combustion heat - energy in faeces
ME = DE - energy in urine - fermentation energy
ME = DE - energy in urine - fermentation energy
What is net energy (NE)?
NE = metabolizable energy - heat loss - specific dynamic action
NE = DE - energy in urine - fermentation energy
The energy content of the foodstuff measure in bomb calorimeter
NE = combustion heat - energy in faeces - energy in urine
NE = metabolizable energy - heat loss - specific dynamic action
In which species can the metabolizable energy be determined directly?
Ruminants
birds
carnivores
none of the above
Birds (they defecate and urinate at the same time through the cloaca)
Which forms of energy can cover the needs of vital processes or can be utilized for production?
Metabolizable energy
Digestible energy
Net energy
Gross energy
Net energy
What portion of the gross energy is lost with the urine?
20 %
10-60%
5-12%
3-5%
3-5%
How much energy is lost with 1 mol of uric acid?
1925 kJ
634 kJ
1254 kJ
135 kJ
1925 kJ
What portion of the metabolizable energy is converted into net energy during pregnancy?
70 %
20 %
30-40%
90 %
20%
What portion of the metabolizable energy can be used for vital processes?
30-40%
90 %
70 %
20 %
70%
What is the basal metabolic rate?
The energy which is used to maintain constant body temperature
The energy which is used for vital processes
The energy production measured in standstill stage
The energy production measured in resting stage
The energy production measured in resting stage
What criteria determine the basal metabolic rate?
Complete resting, lying posture, absence of any psychic excitement, and neutral environmental temperature
natural environmental temperature, lying posture or having a rest, before morning feeding
standing posture, absence of any psychic excitement, and neutral environmental
temperature
Complete rest, standing posture, fasting
Complete resting, lying posture, absence of any psychic excitement, and neutral environmental temperature
Very hard to measure on animals
What criteria determine the resting metabolic rate?
Complete rest, lying posture, fasting, neutral environmental temperature
lying posture or having a rest, before morning feeding
can be measure only in humans, before food uptake, in absence of any psychic excitement
the specific dynamic action and the production energy have to be subtracted from the basal metabolic rate
Lying posture or having a rest, before morning feeding
What is the metabolic spectrum?
The energy turnover that is independent of the activity and production
Metabolic rate above the resting metabolic rate, which can be determined by measuring the oxygen consumption
Energy turnover above the basal metabolic rate (or resting metabolic rate)
Energy turnover which can be up to 100 folds of basal metabolic rate
Energy turnover above the basal metabolic rate (or resting metabolic rate)
Which statement is true for the Lavoisier’s calorimetry?
The advantage is that it can be used on physically active animals
The water evaporated is absorbed by either H2SO4 or NaCO3
Water of known temperature is circulated in a copper tube in the heat isolated chamber; water is warmed up by the animal
The chamber, containing the animal, was surrounded by ice; the amounts of melted ice and the water being produced, were used for the estimation of heat generation
The chamber, containing the animal, was surrounded by ice; the amounts of melted ice and the water being produced, were used for the estimation of heat generation
How much energy is needed to melt 1 g of ice?
- 334 kJ
- 334 kcal
- 585 kcal
- 585 kJ
0.334 kJ
Which statement is true for the complex direct calorimetry?
The disadvantage is that it cannot be used on physically active animals
Water of known temperature is circulated in a copper tube in the heat- isolated chamber; water is warmed up by the animal
The chamber, containing the animal, was surrounded by ice; the amounts of melted ice and the water being produced, were used for the estimation of heat generation
Produced heat can be calculated by the energy which is needed to melt the ice
Water of known temperature is circulated in a copper tube in the heat-isolated chamber; water is warmed up by the animal
Which statement is true for the compensation calorimetry?
Water of known temperature is circulated in a copper tube in the heat- isolated chamber; water is warmed up by the animal
A double-walled chamber, the inner wall of which is a good conductor of heat, and the outer wall of which is kept under constant temperature.
The amount of heat dissipated through the wall of the chamber is measured in a way that the heat-difference
There are two chambers with identical thermal capacity, connected together and placed in a space with constant temperature; one of them contains the animal, the other a lamp
Measures the heat which is lost by radiation, conduction, and convection
There are two chambers with identical thermal capacity, connected together and placed in a space with constant temperature; one of them contains the animal, the other a lamp
Which statement is true for the gradient calorimetry?
Its disadvantage that it is complicated and not accurate
Measures only the heat which is lost by conduction
There are two chambers with identical thermal capacity, connected together and placed in a space with constant temperature; one of them contains the animal, the other a lamp
A double-walled chamber, the inner wall of which is a good conductor of heat, and the outer wall of which is kept under constant temperature. The amount of heat dissipated through the wall of the chamber is measured in a way that the heat- difference
4?
Why is the indirect calorimetry applied to monitor the energy balance?
More than 95% of energy utilized by the body is originated from the chemical reaction between oxygen and foodstuffs therefore the O2 is a reliable marker for energy turnover
Oxygen consumption gives information about the quality of food
The O2 is a reliable marker for energy turnover even during heavy physical activity
During combustion of 1 litre of oxygen, 20.18 J (4.825 cal) of energy is released
More than 95% of energy utilized by the body is originated from the chemical reaction between oxygen and foodstuffs therefore the O2 is a reliable marker for energy turnover
What is oxygen equivalency?
During combustion of 1 mol of oxygen, 1 mol of CO2 is released
During combustion of 1 litre of oxygen, 20.18 kJ (4.825 kcal) of energy is released
Combustion of 1 g fat requires the same amount of oxygen as 1 g carbohydrate
During combustion of 1 litre of oxygen, 20.18 J (4.825 cal) of energy is released
During combustion of 1 litre of oxygen, 20.18 kJ (4.825 kcal) of energy is released
What is the advantage of indirect calorimetry?
The O2 is a reliable marker for energy turnover even during heavy physical activity
Oxygen consumption gives information about the quality of the food
the animal can stay in its natural environment, it can move freely
there are no separate open and closed systems
the animal can stay in its natural environment, it can move freely
What is the disadvantage of indirect calorimetry?
During combustion of 1 litre of oxygen releases different amount of energy depending on the food quality
It is difficult to apply, the method is slow
The animal has to stay inside the laboratory
The method measures only O2- dependent energy production
The method measures only O2- dependent energy production
Which is the normal setup for open- system indirect calorimetry?
The amount and composition in the expired air is measured
The amount and CO2 content in the inspired air is measured
The amount and CO2 content in the expired air is measured
The amount and composition in the inspired air is measured
The amount and composition in the expired air is measured
What instrument is an open-system indirect calorimeter?
Krogh’s device
Douglas bag
Knipping device
Haldane calorimeter
Douglas bag
Which is the normal setup for closed- system indirect calorimetry?
The amount and CO2 content of the expired air is measured and the oxygen consumption is deduced
The animal inspires from a closed bag and expires to the outside air
The animal is completely isolated from the outside air
The animal inspires from the outside air and expires into a closed bag
The animal is completely isolated from the outside air
What is the setup of the Krogh’s device?
Expired CO2 can be measured by absorbing it with KOH
The oxygen used up is replenished and the volume measured
The device gives the possibility to measure both the oxygen consumption and the CO2 production
Oxygen is added previously to the system, then the amount of consumed oxygen is measured
Oxygen is added previously to the system, then the amount of consumed oxygen is measured
What is the respiratory quotient?
the volume of carbon dioxide produced divided by the volume oxygen consumed during the same time period
the volume of carbon dioxide produced minus the volume oxygen consumed during the same time period
the volume of carbon dioxide expired divided by the volume oxygen inspired during the same time period
gives information about the amount of fat, protein, and carbohydrate utilized
the volume of carbon dioxide produced divided by the volume oxygen consumed during the same time period
Combustion of which nutrient gives the most energy while using up 1 liter of oxygen?
Protein
Carbohydrate
Fat
the energy released is the same for all three nutrients above
Carbohydrates
What is the normal range of RQ?
0-1
0-10
0.7-1.0
0.5-0.7
0.7-1.0
What is RQ?
The respiratory quotient (or RQ or respiratory coefficient), is a dimensionless number used in calculations of basal metabolic rate (BMR) when estimated from carbon dioxide production. It is calculated from the ratio of carbon dioxide produced by the body to oxygen consumed by the body
