Chapter D

Question 1

critical to ATP supply in first few minutes of exercise

Answer 1

Glycolysis

Question 2

Rate of glycolysis and amount ATP production possible determined by

Answer 2

1. Training status
2. Muscle mass
3. Substrate availability

Question 3

Glycolysis meets —– of energy demands in an event lasting 2 min

Answer 3

60%

Question 4

Glycolysis meets —– of energy demands in an event lasting 4 min

Answer 4

30%

Question 5

Glycolysis meets —– of energy demands in an event lasting over 30 min

Answer 5

<5%

Question 6

How does NADH provide energy?

Answer 6

Electrons shuttled through oxidative phosphorylation to generate energy

Question 7

How does pyruvate provide energy?

Answer 7

Shuttled to mitochondria for complete oxidation or

Converted to lactate

Question 8

What is the only source of energy for RBC?

Answer 8

Glycolysis

Why?
Bc they have no mitochondria

Question 9

Major source of ATP for muscles under sever exercise conditions

Answer 9

Glycolysis

Question 10

Immediate intake post exercise promotes

Answer 10

Glucose transport and glycogen synthesis for use in next training session

Question 11

Glucose from diet is phosphorylated to

Answer 11

Glucose 6 phosphate in cell

Question 12

Glucose from glycolysis is phosphorylated to

Answer 12

Glucose 1 phosphate

Question 13

What does Phosphorylation do?

Answer 13

Traps glucose in cell

Question 14

3 roles of glycolysis

Answer 14

Generate ATP directly
Generate NADH
Generate pyruvate

Question 15

When does glycolysis predominate as energy-yielding pathway?

Answer 15

1. During rapid change from rest to activity; or rapid change from low to high intensity
2. During exercise when oxygen is limited (especially isometric)
3. When VO2 is 60% or more of VO2
   max

Question 16

Glycolytic pathway regulation deepens on concentration of

Answer 16

1. Glucose
2. Glycogen
3. Glucose 6 phosphate
4. ADP

Question 17

Need for glycolysis determined by

Answer 17

Rate of ATP hydrolysis

Question 18

ADP phosphorylation achieved by 2 glycolytic enzyme

Answer 18

1. Phosphoglycerate kinase

2. Pyruvate kinase

Question 19

Primary targets for regulation of glycolytic pathway ?

Answer 19

3 irreversible reactions of glycolysis

1. Hexokinase
2. phosphofructokinase
3. Pyruvate kinase

Question 20

Regulation of hexokinase

Answer 20

Regulated by produce of its reaction
If G6P increases too much, binds to hexokinase and slows reaction

Added effect of slowing glucose uptake into cell (limit substrate)

Question 21

Major regulatory enzyme

Answer 21

Phosphofructokinase

Question 22

List regulators of PFK1 activity

Answer 22

ATP
Citrate 
ADP/AMP
Pi
F2,6 bisphosphate

Question 23

How does ATP regulate PFK1

Answer 23

Allosteric inhibitor
Allosteric inhibition enhanced by H
Bind to negative allosteric site

Question 24

How does citrate regulate of PFK1 activity

Answer 24

Provides index of fuel and ATP sufficiency

FA metabolism for ATP production increases citrate production

Question 25

How do ADP/AMP regulate PFK1 activity?

Answer 25

Small changes in ATP lead to big changes in ADP and AMP concentration

Question 26

How does Pi regulate PFK1 activity

Answer 26

During PCr regeneration of ATP, decrease in PCr inversely related to Pi concentration Helps relieve H inhibition of PFK

Question 27

Lactate might actually protect from fatigue due to

Answer 27

Loss of intracellular potassium

Question 28

Potential sources of fatigue in working muscle

Answer 28

Depletion of phosphogens/increase in Pi Change in intramuscular pH

Question 29

PH changes during exercise What is pH at rest?

Answer 29

7.4

Question 30

PH changes during exercise What is pH after high intensity exercise

Answer 30

7

Question 31

PH changes during exercise What is pH at point of fatigue

Answer 31

6.3

Question 32

High [H+] affects fatigue in 2 ways:

Answer 32

1. inhibit glycolysis (does it?) 2. directly interfere with contractile mechanism (at physiologic temperature, does it?) 3. stimulate free nerve endings in muscle → pain)

Question 33

What to do for recovery after exercise

Answer 33

Restore muscle Pcr and ATP Remove accumulated lactate Restore normal pH Replace glycogen stores