Question 1

Which of the following best describes the primary energy system used during a 10-second all-out sprint?

Accepted Answer

ATP-PCr (phosphagen) system

Question 2

During high-intensity exercise lasting 30–120 seconds, which metabolic pathway is primarily responsible for ATP production?

Accepted Answer

Anaerobic glycolysis (lactic acid system)

Question 3

Which of the following equations correctly represents the reaction catalyzed by creatine kinase during muscle contraction?

Accepted Answer

$$\mathrm{Creatine\ phosphate} + \mathrm{ADP} \rightarrow \mathrm{Creatine} + \mathrm{ATP}$$

Question 4

Which muscle fiber type is most resistant to fatigue and best suited for maintaining posture?

Accepted Answer

Slow oxidative fibers (Type I)

Question 5

A marathon runner relies primarily on which energy system for ATP production during the majority of the race?

Accepted Answer

Aerobic respiration (oxygen system)

Question 6

Which of the following is a direct result of anaerobic glycolysis in muscle cells?

Accepted Answer

Formation of lactic acid

Question 7

What is the main cause of muscle fatigue during prolonged, high-intensity exercise?

Accepted Answer

Ionic imbalances and increased inorganic phosphate

Question 8

Which process is responsible for replenishing muscle glycogen stores after exercise?

Accepted Answer

Excess postexercise oxygen consumption (EPOC)

Question 9

Which of the following best explains why fast glycolytic fibers fatigue more quickly than slow oxidative fibers?

Accepted Answer

They rely primarily on anaerobic glycolysis for ATP

Question 10

A patient is unable to regenerate ATP quickly during short, intense exercise. Which enzyme is most likely deficient?

Accepted Answer

Creatine kinase

Question 11

Which of the following is NOT a function of ATP in muscle contraction?

Accepted Answer

Generating action potentials in neurons

Question 12

Which of the following best describes the fate of lactic acid produced during intense exercise?

Accepted Answer

It is converted to pyruvic acid or glucose in the liver

Question 13

Which muscle fiber type would be most prevalent in the quadriceps of an elite sprinter?

Accepted Answer

Fast glycolytic fibers (Type IIb)

Question 14

Which of the following statements about aerobic respiration is TRUE?

Accepted Answer

It requires oxygen and occurs in mitochondria

Question 15

Which of the following best explains why fatty acids become the main fuel source after 30 minutes of aerobic exercise?

Accepted Answer

Glycogen stores are depleted and aerobic lipolysis predominates

Question 16

Which of the following is a characteristic of fast oxidative fibers (Type IIa)?

Accepted Answer

High myoglobin content and intermediate fatigue resistance

Question 17

A person with a high percentage of slow oxidative fibers would excel in which activity?

Accepted Answer

Marathon running

Question 18

Which of the following best describes the process of excess postexercise oxygen consumption (EPOC)?

Accepted Answer

Oxygen is used to convert lactic acid to pyruvic acid and replenish ATP stores

Question 19

Which of the following is a product of aerobic respiration?

Accepted Answer

Carbon dioxide and water

Question 20

Which of the following best explains why all fibers in a single motor unit are the same type?

Accepted Answer

They are innervated by the same motor neuron, which determines their metabolic properties

Muscle Physiology: Muscle Metabolism and Fiber Types

Study Guide - Practice Questions