Lab 5: Membrane Potential

Question 1

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

Answer 1

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

Question 2

Energetic equivalent (EE):

Answer 2

• Is the equivalent relating the released energy and O2 mass
• Tells us how much energy is released utilizing 1 L of O2

Question 3

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

Answer 3

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

Question 4

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%

Answer 4

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%

?????

Question 5

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

Answer 5

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

Question 6

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

?

Question 7

Which was/were the substantial risk of BMR measurement for rat in closed metabolimeter?

• O2 deficiency
• Overheating
• CO2 build-up
• Anesthesia

?

Answer 7

Which was/were the substantial risk of BMR measurement for rat in closed metabolimeter?

• O2 deficiency
• Overheating
• CO2 build-up
• Anesthesia

Question 8

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

Question 9

Aerobic and anaerobic metabolism could equal:

• Under basal conditions
• During heavy exercise
• In childhood only
• Only for short period of time

Question 10

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)

Question 11

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

Question 12

Thermoneutral condtion for BM required:

• To reduce max energetic needs for thermoregulation

Answer 12

*

Question 13

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)

Question 14

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

Question 15

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

Question 16

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

Question 17

Individual can gain weight:

• If MR is less than energy content of received food
• If BMR is less than energy content of received food

Question 18

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)

Question 19

Amount of O2 in classroom:

• Is sufficient for resting metabolism of man for about a week
• Can vary if classroom is empty

Question 20

All the following factors increase BMR except:

• Age
• Anxiety
• Increase of body temperature
• Decrease of the body temperature
• Body surface

Question 21

Metabolism Definition

Answer 21

•Sum of all physical and chemical reactions in the body in order to sustain life

Question 22

Adenosine Triphosphate (ATP): X calories per mole under standard condition?

Answer 22

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.

Question 23

ATP is generated by combustion of carbohydrates, fats and proteins…

Combustion of carbohydrates:

Answer 23

mainly glucose but other sugars such as fructose through glycolysis in the cytoplasm and the citric acid cycle in the mitochondria.

Question 24

ATP is generated by combustion of carbohydrates, fats and proteins…

Combustion of fatty acids:

Answer 24

Combustion of fatty acids in the cell mitochondria by beta-oxidation.

Question 25

ATP is generated by combustion of carbohydrates, fats and proteins... Combustion of proteins:

Answer 25

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.

Question 26

Phosphocreatine

Answer 26

* 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.

Question 27

Carbohydrates

Answer 27

Question 28

Lipids

Answer 28

Question 29

Protiens

Answer 29

Question 30

Stages of fasting

Answer 30

Question 31

Metabolic Rate

Answer 31

•The rate of heat liberation/metabolism during chemical reactions per unit time

Question 32

Types of MR

Answer 32

1. Basal metabolic rate (BMR) 2. Resting metabolic rate (RMR)

Question 33

What influences the MR?

Answer 33

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.