Exam 1: Anaerobic Metabolism During Exercise

Question 1

What are some reasons why Anaerobic ATP is needed at the onset of exercise (why is aerobic ATP provision not adequate?)

Answer 1

• Aerobic metabolism is too slow

- It takes a couple minutes for the process to occur

Question 2

Anaerobic ATP production is needed at 2 points:
1)
2)

Answer 2

Onset of exercise

During intense exercise

Question 3

Anaerobic metabolism is defined as the ability of the metabolic pathways in muscle to generate ATP without the immediate use of ________.

Answer 3

oxygen

Question 4

ATP concentration is well maintained during _______ exercise.

During very intense exercise, the concentration of ATP only decreases by ~20% to 50% below its resting level.

Resting ATP stores are at ~25 mmol/kg dm.

• This amount would be used up in about 1 second of maximal effort or 15 seconds of intense exercise if not replenished.
• The concentration of PCr in skeletal muscle is ~75 mmol/kg dm.

Answer 4

aerobic

Explanation: ATP concentrations are well maintained during low to moderate exercise through the replenishment of ATP from energy systems always at work. It is only when exercise is too intense, such as a Wingate cycle test, that ATP levels drop significantly. This occurs because there is not enough time for ATP to be replenished and be maintained with the increased intensity.

Question 5

When you go for a slow-long distance run, light-moderate intensity, ___ doesn’t change too much, but ___ levels increase.

Answer 5

ATP
ADP

Explanation: when you see ADP “think exercise”. ADP levels increase because phosphates are being broken down from ATP, which then need to be re-phosphorylated to ATP again via either the creatine kinase reaction (during intense) or adenylate kinase (during very high-intense exercise).

Question 6

Aerobic metabolism is not sufficient under certain circumstances…

Anaerobic production of ATP “assists” aerobic metabolism during:

• The ____ it takes for the aerobic system to reach the desired rate of ATP production at the onset of exercise.
• Exercise _______ where the power output is increased.
• Times when the maximal rate of ATP production is ____ than required by the muscles during intense activities (greater than VO2max).

Answer 6

time
transitions
less

Question 7

Anaerobic ATP production is virtually ___________ at the onset of exercise.

• This is to cover the initial shortfall in aerobic ATP provision.
• The amount of energy required in the transition to exercise is referred to as the ______ _______.

Answer 7

instantaneous

oxygen deficit

Question 8

Sources of Anaerobic ATP

3 sources/pathways of anaerobic ATP production…

1) Reaction catalyzed by ________ ______
- -degradation of PCr (phosphocreatine)
2) Glycogenolysis/glycolysis
3) Reaction catalyzed by ________ ______ (small capacity)

Answer 8

creatine kinase

adenylate kinase

Question 9

The phosphagen system consists of which pathways of ATP production?

1) Reaction catalyzed by creatine kinase
- -degradation of PCr (phosphocreatine)
2) Glycogenolysis/glycolysis
3) Reaction catalyzed by adenylate kinase (small capacity)

Answer 9

1) Creatine kinase

2) Adenylate kinase

Question 10

What is the fastest reaction known to man?

Answer 10

Creatine kinase

Question 11

Degradation of PCr…

PCr + ADP + H(+) —— ATP + Cr

Increases in the concentration of ADP alter the equilibrium of this reaction and stimulate CK (creatine kinase) to convert ____ to ATP.

Answer 11

PCr

Question 12

What is the creatine kinase reaction?

Answer 12

ADP + PCr —– ATP + Cr

Question 13

The onset of exercise uses _______ ____.

Answer 13

stored ATP

Question 14

What is the adenlyate kinase reaction?

Answer 14

ADP + ADP —— ATP + AMP

Question 15

During exercise, when does the adenylate kinase reaction occur?

Answer 15

During high-intensity exercise