Exam 1 Test Questions

Question 1

Measuring energy consumption by heat given off by the body would be assessed by:

A: indirect calorimetry
B: expired gas analysis
C: bomb calorimetry
D: direct calorimetry

Answer 1

D: direct calorimetry

Question 2

Blocking creatine kinase would likely cause which of the following in the cell?

A: increased glycogen
B: increased AMP
C: increased ATP
D: increased glucose

Answer 2

B: increased AMP

Question 3

Decreased amounts of NADH will have what effect on the succinate dehydrogenase reaction?

Answer 3

Increased

Question 4

During a 30 second, high intensity exercise, ATP concentration changes little. This is largely due to:

A: high contribution of aerobic ATP production
B: unchanging ATP demand compared to rest
C: breakdown of PCr to make ATP

Answer 4

C: breakdown of PCr to make ATP

Question 5

Joe and Bob have been competing against each other in road races for years. Despite having a similar VO2max, Joe always beats Bob in the race. Which of the following could explain why? (select all that apply)
A: Joe has a better running economy than Bob.
B: Joe maintains the same pace as Bob but at a lower oxygen consumption, leaving him more energy to outsprint Bob at the end.
C: Joe is able to run at a faster pace than Bob, while maintaining the same percentage of VO2max throughout the race.

Answer 5

A: Joe has a better running economy than Bob.
B: Joe maintains the same pace as Bob but at a lower oxygen consumption, leaving him more energy to outsprint Bob at the end.
C: Joe is able to run at a faster pace than Bob, while maintaining the same percentage of VO2max throughout the race.

Question 6

After completing her warm-up on the treadmill, Allyson increases the speed on the treadmill to 6.0 mph and jogs for 30 minutes. What would you expect to happen to her VO2 between 5 and 20 minutes of exercise?

Answer 6

Remain the same

Question 7

Carbohydrate is often called the preferred fuel of the body because: (select all that apply)

A: it is the only nutrient that can be used to produce ATP anaerobically
B: it requires more oxygen to be metabolized than fat
C: it is the only substrate that can be used by certain tissues such as nerves

Answer 7

A: it is the only nutrient that can be used to produce ATP anaerobically
C: it is the only substrate that can be used by certain tissues such as nerves

Question 8

The common entry point into oxidative metabolism for triglycerides, carbohydrates and protein is:

A; acetyl CoA
B; lactate
C: citrate
D: pyruvate

Answer 8

A; acetyl CoA

Question 9

During exercise of increasing intensity, what is the lactate threshold?

Answer 9

the point at which lactate begins to accumulate faster than it is consumed

Question 10

How many NADH from 1 acetyl CoA passing through the Krebs cycle?

Answer 10

3

Question 11

During recovery after exercise, the creatine kinase reaction would cause which of the following in the cell?

A: increased glucose
B: increased ATP
C: increased PCr
D: increased inorganic phosphate

Answer 11

C: increased PCr

Question 12

The rate limiting enzyme of glycolysis is

Answer 12

phosphofructokinase

Question 13

How many net ATP are produced directly from glucose going through glycolysis?

Answer 13

2

Question 14

Curly is an untrained, stay-at-home couch potato who rarely moves. Larry is an elite cross-country skier. Which set of values is most likely representative of their respective VO2max scores?

A: 0.25 ml/kg/min vs. 2.5 ml/kg/min
B: 5 ml/kg/min vs. 110 ml/kg/min
C: 25 ml/kg/min vs. 45 ml/kg/min
D: 40 ml/kg/min vs. 80 ml/kg/min

Answer 14

D: 40 ml/kg/min vs. 80 ml/kg/min

Question 15

High concentrations of NADH would inhibit which of the following? (select all that apply)

A: hexokinase
B: citrate syntase
C: alpha ketoglutarate dehydrogenase
D: pyruvate dehydrogenase

Answer 15

B: citrate syntase
C: alpha ketoglutarate dehydrogenase
D: pyruvate dehydrogenase

Question 16

1 gram of fat has approximately ____ kcals.

Answer 16

9

Question 17

How many times does a 16 carbon fatty acid go through beta oxidation?

Answer 17

7

Question 18

Increased [citrate] would have what effect on the pyruvate kinase reaction?

Answer 18

decreased

Question 19

What is the difference between RQ and RER?

Answer 19

One represents the ratio of CO2/O2 at the cellular level, while the other represents the ratio in expired air.

Question 20

You eat a nice, big, juicy baked potato with no toppings. The carbohydrate from that potato that is completely combusted by your body will ultimately be released back to the environment as:

A: ADP (excreted in urine, sweat and breathing) and CO2 (breathed out)
B: water (excreted in urine, sweat, and breathing) and simple carbon chains (excreted in the feces)
C: CO2 (breathed out) and water (excreted in urine, sweat, and breathing)
D: lactate (excreted in urine) and water (excreted in urine, sweat and breathing)

Answer 20

C: CO2 (breathed out) and water (excreted in urine, sweat, and breathing)

Question 21

An increase in the hexokinase reaction may be due to which of the following?

A: increased pyruvate
B: decreased glucose-6-phosphate
C: increased PCr
D: decreased ATP

Answer 21

D: decreased ATP

Question 22

The hexokinase reaction is stimulated by:

A: increased glucose
B: increased NADH
C: increased lactate
D: increased acetyl CoA

Answer 22

A: increased glucose

Question 23

How many FADH2 are produced by the Kreb’s cycle each time it cycles through completely?

Answer 23

1

Question 24

How many ATP are generated from the complete combustion of glucose?

Answer 24

30

Question 25

What does a kilocalorie measure?

Answer 25

the heat released by food

Question 26

What is the difference between the first reaction in glycolysis in skeletal muscle (hexokinase reaction) compared to the same reaction in the liver (glucokinase)? How does the difference alter the flow of potential energy (as glucose) in the body?

Answer 26

The first reaction of glycolysis is a very highly exergonic reaction that effectively traps the glucose molecule into the skeletal muscle. In the liver, this reaction is not as energy consuming, and is not undergone as easily.

This difference allows for glucose to leave the liver where it is not as needed, and flow to other tissues in the body that need it to complete work. For example, the glucose from the liver can go to the muscle or even the nervous system.

Question 27

What is the oxygen deficit? What causes it?

Answer 27

The O2 deficit refers to the inability to consume enough oxygen as is needed at the onset of the exercise. The O2 debt is caused by the fact that moment you begin exercising, your body has an immediate high need for ATP, but our increased O2 consumption is not as immediate to take place. Therefore, at the beginning, we use our ATP PCR system to generate ATP until we reach our steady-state O2 consumption. This lag in time between the need for increased O2 and the time it takes to reach that O2 consumption value is plotted on a chart, and the area between the O2 required by ATP need and O2 actually able to be consumed is the O2 deficit.

Question 28

State the first and second laws of thermodynamics. During the growth of a human being we add cells, organs, and create complex systems from a single cell. Does this growth obey these laws, why or why not?

Answer 28

First law: Law of conservation of E: E cannot be created or destroyed
Second law: All E goes toward entropy/ disorder

Although it may seem counter intuitive at first, the growth of a human does indeed obey these laws. Although it seems like a developing human is producing cells in an orderly manner, in reality there is more disorder occurring. The large amount of energy required to have these cells divide and multiple in an “orderly” way produces much more heat and disorder in the body than it does the actual cellular quantity. So, while the energy is going to produce the new cells of the body, much more of the energy is being given off as heat and used to complete these divisions, and therefore, is more disorderly.

Question 29

Earlier this month, Mo Farah set a new world record for distance covered in 1 hr. He ran for 21.322 kilometers (13.249 miles) giving him an average speed of 13.249 miles/hour or 5.922 meters/second. Given the metabolic cost of running (make sure to add in his resting MET too) what is his predicted VO2 during this hour? He weighs 58 kg and given an energy expenditure of 5.0 kcal/L O2 consumed, how many calories did he expend during the hour?

Answer 29

1,297 kcals expended

His metabolic cost of running: 3.6 ml/kg/min + 0.2(60min*5.922m) = 74.56 ml/kg/min

74. 56ml/kg/min x 60min x 58kg = 259,482.72 ml or 259.5 L
75. 0kcal/LO2 * 259.5 L = 1,297 kcals expended

Question 30

During a 20 minute walk, Willow consumed 1.5 L of oxygen/min and blew off 1.8 L of carbon dioxide/min. What is his RQ? How many kcals did she consume during the walk, and how many from carbohydrate and how many from fat?

Answer 30

RQ = VCO2/VO2 = 1.8L CO2/1.5LO2 = 1.2

— therefore RQ >1.0 meaning that there is a high deposition of fat from carbohydrates

1.5 LO2/min x20 min = 30 L O2

30 LO2 * 5.047 kcal/LO2 = 151.41 kcal all from carbohydrates and none from fat

Question 31

What is the equation for RQ

Answer 31

VCO2/VO2

Question 32

During a high intensity exercise bout the electron transport chain reaches a point where electrons cannot get shuttled any faster, what would be the expected effect on [NADH]? How would this change in [NADH] affect the Krebs cycle? How would this change affect [lactate]? How would this change affect the substrate (macronutrient) being used to generate ATP?

Answer 32

The [NADH] would begin to increase because it would be accumulating rather than enter into the ETS to produce energy.

This increased [NADH] would directly influence the rate limiting enzyme of the Krebs cycle, isocitrate dehydrogenase, to slow down the reaction and therefore slow down the krebs cycle itself.

This would cause the [lactate] to increase because the Krebs cycle is slowing down, not allowing for pyruvate to enter in. So, LDH will take pyruvate and convert it into lactate instead.

Instead of using glucose now to generate ATP, we will turn to fat molecules to produce ATP in the body.