Lab 5: Membrane Potential Flashcards
Actual MR:
- Could not exceed the aerobic MR
- Of one individual could be lower than BMR of another individual
- OF one individual could be higher than BMR of another individual
- For the same individual must be higher than his/her BMR
Actual MR:
- Could not exceed the aerobic MR
- Of one individual could be lower than BMR of another individual
- OF one individual could be higher than BMR of another individual
- For the same individual must be higher than his/her BMR
Energetic equivalent (EE):
- Is the equivalent relating the released energy and O2 mass
- Tells us how much energy is released utilizing 1 L of O2
Which is/are likely results of MR measurement in lab?
- 10% above BMR
- 15% of BMR
- 6000KJ/day for a female student
- 100W for a male student
Which is/are likely results of MR measurement in lab?
- 10% above BMR
- 15% of BMR
- 6000KJ/day for a female student
- 100W for a male student
In long-term perspective (months), how much energy is approximately released by metabolism compared to energy intake (food)?
- 100% intake should equal output
- 66%
- 33%
- 0%
In long-term perspective (months), how much energy is approximately released by metabolism compared to energy intake (food)?
- 100% intake should equal output
- 66%
- 33%
- 0%
?????
O2 stored in body:
- Is negligible compared to daily need (less than 1%)
- Accounts for 500ml
- Would cover O2 consumption for less than 10 minutes
O2 stored in body:
- Is negligible compared to daily need (less than 1%)
- Accounts for 500ml
- Would cover O2 consumption for less than 10 minutes
Suppose O2 consumption 400ml/min, cardiac output 8L/min. Oxygen saturation of mixed venous blood would be:
- 75%
- 150ml O2/L blood
- Same as typically at rest
- Higher if 100% O2 would be inhaled
?
Which was/were the substantial risk of BMR measurement for rat in closed metabolimeter?
- O2 deficiency
- Overheating
- CO2 build-up
- Anesthesia
?
Which was/were the substantial risk of BMR measurement for rat in closed metabolimeter?
- O2 deficiency
- Overheating
- CO2 build-up
- Anesthesia
Basal metabolism:
- Could even be lower than expected table value
- Is significantly lower for people living in higher attitudes (5km) due to lower O2 conc.
- Is significantly lower for people living in higher attitudes (5km) due to colder climate there
- Could only be measured in physiological individuals
Aerobic and anaerobic metabolism could equal:
- Under basal conditions
- During heavy exercise
- In childhood only
- Only for short period of time
Amount of O2 in classroom 6*5*3,3 m (w l h, assume our classroom):
- Is cca 100 000 L
- Is sufficient for resting metabolism of a man for about a week
- May vary
- Would drop by cca 10% at end of 3-hour lab, if classroom is sealed (airproof) and 10 people would attend (all time)
Climbing uphill compared to BMR:
- Could increase actual metabolic rate x5
- Could increase actual metabolic rate x20
- Prevents metabolic rate to be measured directly from heat production
- Cannot be estimated only by O2 consumption
Thermoneutral condtion for BM required:
- To reduce max energetic needs for thermoregulation
*
Fasting preceding BM measurement required due:
- To expenditure of additional energy to digest (reasborb) food
- To expenditure of additional energy to store resorbed food
- To possible intake of nutrients of high energy content
- To changes of respiratory quotient (RQ)
MR:
- Depends on oxygen that is delivered to the tissue
- Linearly depends on O2 conc. in air (pO2 10kPa-100) ?????
- Linearly depends on CO2 conc. in air (pCO2 0Kpa-100)
- Linearly depends on E content of received nutrients
Indirect calorimetry:
- O2 consumption is linearly related to MR only if measured for longer than 5 minutes
- O2 consumption is linearlye related to MR only if basal metabolism measured
Method used to measure MR in class:
- Could only be properly evaluated if atmosphere pressure + ambient temperature are known
- Body volume must be known to get proper O2 consumption in rat
- Need O2 sensor
Individual can gain weight:
- If MR is less than energy content of received food
- If BMR is less than energy content of received food
Energy received in food:
- Could be higher than MR per day
- Could be lower than actual MR per day
- Could be 300% depending on occupation (activity)
Amount of O2 in classroom:
- Is sufficient for resting metabolism of man for about a week
- Can vary if classroom is empty
All the following factors increase BMR except:
- Age
- Anxiety
- Increase of body temperature
- Decrease of the body temperature
- Body surface
Metabolism Definition
•Sum of all physical and chemical reactions in the body in order to sustain life
Adenosine Triphosphate (ATP): X calories per mole under standard condition?
ATP releases 7,300 calories per mole under standard conditions but as much as 12,000 calories under physiological conditions, which is vested in each of its two high-energy phosphate bonds.
Some chemical reactions that require ATP energy use only a few hundred of the available 12,000 calories and the remained of this energy is lost in the form of heat.
ATP is generated by combustion of carbohydrates, fats and proteins…
Combustion of carbohydrates:
mainly glucose but other sugars such as fructose through glycolysis in the cytoplasm and the citric acid cycle in the mitochondria.
ATP is generated by combustion of carbohydrates, fats and proteins…
Combustion of fatty acids:
Combustion of fatty acids in the cell mitochondria by beta-oxidation.
ATP is generated by combustion of carbohydrates, fats and proteins…
Combustion of proteins:
Combustion of proteins which requires hydrolysis to their component amino acids and degradation of amino acids to intermediate compounds of the citric acid cycle and then to acetyl coenzyme A and carbon dioxide.
Phosphocreatine
- Phosphocreatine also contains high-energy phosphate bonds and is three to eight more times more abundant than ATP.
- Also the high-energy bond of phosphocreatine contains about 8500 calories per mole under standard conditions and as many as 13,000 calories per mole under conditions in the body.
- Unlike ATP, phosphocreatine cannot act as a direct coupling agent for energy transfer between food and the functional cellular systems but it can transfer energy interchangeably with ATP.
- When extra amount of ATP are found in the cell they are used to create phosphocreatine building up a store.
- Then when ATP begins to get used up the energy in the phosphocreatine is transferred rapidly back to ATP and then to the functional systems of the cells.
Carbohydrates
Lipids
Protiens
Stages of fasting
Metabolic Rate
•The rate of heat liberation/metabolism during chemical reactions per unit time
Types of MR
- Basal metabolic rate (BMR)
- Resting metabolic rate (RMR)
What influences the MR?
increases:
- Age
- Gender
- Exercise
- Thyroid hormone
- Testosterone
- Growth hormone
- Sympathetic stimulation
- Fever
Decreases
- Sleep
- Malnutrition
- Exercise: You need more energy. The factor that most dramatically increases metabolic rate is strenuous exercise. Maximal muscle exercise can increase the overall heat production of the body for a few seconds to about 50x normal or about 20x normal for more sustained exercise in a well trained individual.
- Fever: Increases MR. Increases the chemical reactions of the body by about 120% for every 10°C rise in temperature.
- Sleep: Decreases MR. MR decreases 10 to 15 % below normal during sleep. This fall is due to two principal factors:
- 1.Decreased tone of the skeletal musculature during sleep.
- 2.Decreased activity of the central nervous system.
- Progesterone: When a woman enters the luteal phase of her menstrual cycle, her BMR will increase by 9%. Presumably, it happens due to elevation of progesterone hormone secretion by the corpus luteum.
