Check Your Understanding - Metabolism + Myofibre Types

Question 1

1. Match the following enzyme to its metabolic pathway: Isocitrate Dehydrogenase, PhospoFructoKinase, Citrate Kinase, Lactate DeHydrogenase, Hexokinase, Pyruvate DeHydrogenase, Citrate Synthase

Answer 1

Isocitrate Kinase + Citrate Kinase = Krebs

Phosphofructokinase + Hexokinase = Glycolosis

Lactate Dehydrogenase = Lactate fermentation

Pyruvate degydrogenase = pyruvate Processing

Question 2

What are the products of ATP hydrolysis?

Answer 2

ADP, P H+ and Energy

Question 3

Which metabolic pathway provides the most immediate energy?

Answer 3

Creatine Phosphoylation

Question 4

Explain the difference between aerobic and anaerobic glycolysis

Answer 4

Aerobic Glycolosis has the Pyruvate changed into Acetyl Coenzyme A and it enters the krebs cycle

Anaerobic Glycolosis has the Pyruvate enter lactate fermentation which aims to replinish NAD+

Question 5

5. What product of lactate production allows glycolysis to continue to function?

Answer 5

NAD+

Question 6

6. Which metabolic pathways use oxygen directly?

Answer 6

Oxidative Phosphorylation

Question 7

7. After 4 hours of exercise, what percent of energy expenditure does glycogen contribute to?

Answer 7

45%

Question 8

8. Why does O 2 consumption remain elevated after muscle contraction has stopped?

Answer 8

ATP becomes depleted and oxygen is needed in excess in to remake ATP through OXPHOS and Beta Oxidation

Question 9

9. What are the defining features of SO, FOG and FG fibres?

Answer 9

SO are smalles diameter, higher mitochondrial density and capillarization, less powerful, fatigue resistance and slow twitch

FG are larger diameter, lower mitochondrial denisty and capillarization, most powerful but most easily fatigued and fast twitch

FOG are intermediate

Question 10

10. What activities would large motor units (i.e., MU with a large number of fibres in them) be recruited for?

Answer 10

Power Lifting, gross movements

Jumping and Explosive Movement

Question 11

11. What is the difference between peripheral and central fatigue?

Answer 11

Peripheral fatigue is due to build up of metabolic byproducts and is at the distal end of the NMJ

Central fatigue