Unit 2 Quizes

Question 1

The rate limiting Enyzme in the Krebs cycle is:

Answer 1

Isocirtracte dehydrogenase

Question 2

The primary purpose of the kerbs cycle is to:

Answer 2

Complete the oxidation of foodstuff using NAD and FAD as electrons carries

Question 3

What is the primary purpose of the elctron trasport chain?

Answer 3

The pirpary purpose of the elctron transport chin is to harvet energy from electrons moving down this pathway to produce ATP and Water

Question 4

For every acetyl-CoA molecule that enters the kerbs cycle ___ molecules of NADH and Molecules of FADH are created?

How many per pyruvate?

Answer 4

3 NADH
1 FADH

You have to double it

Question 5

The Kerbs cycle is also known as the critic acid cycle because __ combiines with __ to produce citrate

Answer 5

oxaloacete; acetyl-CoA

Question 6

In general, the higher the intensity of exercise, the greater the contribution of:

Answer 6

Anaerobic energy production

Question 7

The majority of the energy liberated through oxidative metabolism is actually converted to heat. The calculated efficiency for oxidative phosphorylation is approximately:

Answer 7

34%

Question 8

The total (net) ATP tally from the aerobic breakdown of glucose is:

Answer 8

32 ATP

Question 9

The electrons passed through the electron transport chain from NADH to oxygen release energy to ultimately form ATP. Each NADH molecule is equivalent to:

Answer 9

2.5 ATP

Question 10

Aerobic production of ATP occurs in the:

Answer 10

In the mitochondria called oxidative phosphorylation

Question 11

The bioenergetic pathway that first provides ATP for skeletal muscle at the onset of exercise is:
(which system?)

Answer 11

The ATP-PC system

Question 12

The term oxygen deficit refers to the:

Answer 12

Lag in oxygen consumption at the beginning of exercise

Question 13

The lactate threshold is defined as the work rate or oxygen uptake at which there is an exponential:

Answer 13

Rise in blood levels of lactate.

Question 14

During the “rapid” portion of the excess post-exercise oxygen consumption (EPOC), the excess VO2 is primarily due to:

Answer 14

Restoration of muscle PC and replacement of blood and muscle oxygen stores

Question 15

In general, very heavy exercise lasting 60 seconds utilizes energy production that is:

Answer 15

70% anaerobic / 30% aerobic
(intense exercise = mostly anaerobic)

Question 16

At rest, the VO2 consumption of a 70-kg young adult is approximately:

Answer 16

3.5 ml/kg/min.
0.25 L/min.
250 ml/min.
all correct

Question 17

The exercise intensity that promotes the highest amount of total fat oxidation during exercise is approximately:

1) 30% of VO2 max.
2) 60% of VO2 max.
3) 75% of VO2 max.
4) 90% of VO2 max.

Answer 17

60% of VO2 max.
(Because it’s close to the lactate threshold)

Question 18

A respiratory exchange ratio (R) of 0.95 during steady-state exercise is suggestive of a(n):

Answer 18

High rate of carbohydrate metabolism

(Closer to 0.7= fats. closer to 0.1 = Carbs)

0.95= closer to carbs

Question 19

In a healthy individual consuming a nutritionally-balanced diet, most of the carbohydrate used as a substrate during very heavy exercise comes from:

1) muscle glycogen stores.

2) blood glucose.

3) liver glycogen stores.

4) glycogen stored in fat cells.

Answer 19

Muscle glycogen—

because you are using the muscle and that is where it is immediately available

Question 20

The slow rise in oxygen consumption over time during prolonged exercise (at a constant sub-maximal load) in a hot environment is due, in part, to:

(Never see a steady state)

Answer 20

rising blood levels of epinephrine and norepinephrine.

Oxygen never plato’s, only climbs called: VO2 Drift

Question 21

As exercise intensity increases, there is a progressive increase in the reliance of carbohydrate metabolism in the exercising skeletal muscles. This observation is described as the:

Answer 21

crossover concept.

Question 22

The primary fuel source during high-intensity (85% VO2 max) exercise is:

muscle glycogen.

blood glucose.

muscle triglycerides.

plasma FFA.

Answer 22

muscle glycogen—

Higher intensity= pull from glycogen.

Doesn’t have time to grab it from anything else but the muscle

Question 23

Which of the following is true concerning VO2 max?

It occurs at a lower intensity of exercise than the lactate threshold.

It is the maximal volume of oxygen that can be moved into the lungs in one minute.

It is a valid measure of cardiovascular fitness.

It is the highest VO2 achieved during prolonged steady-state exercise.

Answer 23

It is a valid measure of cardiovascular fitness.

Question 24

Which of the following exercise intensities would rely primarily on carbohydrate as a fuel source?

Answer 24

carbs, higher intensity, closer to 1.0

90% of VO2 max.

Question 25

Which physiological factors are potential mechanisms to explain the lactate threshold?

Answer 25

accelerated rate of glycolysis due to epinephrine

recruitment of fast-twitch muscle fibers
(makes more lactate)

reduced rate of lactate removal from the blood
(body can’t clear lactate fast enough)

Question 26

Energy to run a maximal effort 400-meter race (i.e., duration 50 to 60 seconds) comes from:

Answer 26

a combination of aerobic/anaerobic metabolism, with most of the ATP coming from anaerobic sources.

Question 27

The energy to perform long-term, submaximal exercise (i.e., >30 minutes) comes primarily from:

Answer 27

aerobic metabolism.

Question 28

Energy to run a 40-yard dash comes:
(sprint)

Answer 28

almost exclusively from the ATP-PC system.

Question 29

The excess post-exercise oxygen consumption (EPOC) is generally higher following intensive exercise when compared with moderate exercise because intensive exercise:

Answer 29

results in greater body heat gained,

greater PC depleted, higher blood levels of epinephrine and norepinephrine,

and higher blood lactate levels.

Question 30

Which of the following statements is true about muscle ATP production during exercise?

During severe, short-duration exercise (e.g., 10 seconds), muscle ATP production is dominated by the ATP-PC system.

Severe exercise lasting 20-30 seconds relies primarily on aerobic (“slow”) glycolysis to produce the needed ATP for muscular contraction.

Very heavy exercise lasting 45-60 seconds uses a relatively equal combination of the ATP-PC system and protein catabolism to produce the needed ATP for exercise.

All of these statements are true.

Answer 30

During severe, short-duration exercise (e.g., 10 seconds), muscle ATP production is dominated by the ATP-PC system.

Question 31

The measurement of VO2 max is commonly performed during a graded exercise test on a treadmill. However, some subjects will voluntarily terminate an incremental exercise test without reaching VO2 max. The primary (gold standard) criteria to determine if a subject reached their *“true” VO2 *max during an exercise test is:

Answer 31

a plateau in oxygen uptake with an increase in work rate.

Question 32

During steady-state exercise, an R of 0.73 would indicate:

Answer 32

a relatively high level of fat metabolism.

Question 33

When using the R to estimate fuel usage during exercise, the role that protein plays as a fuel source is often ignored. Why?

Answer 33

because protein generally plays a relatively small role as a fuel source during exercise

(Last resort)

Question 34

Carbohydrate used as a fuel source during exercise comes from both blood glucose and muscle glycogen. The relative contribution of these two sources of carbohydrate varies as a function of:

Answer 34

Both “exercise intensity” and “exercise duration” are correct.

Question 35

The process of breaking down triglycerides into free fatty acids and glycerol is called:

Answer 35

lipolysis.

(Lipase is the enzyme)