$$\mathrm{MA} = \frac{\text{Length of effort arm}}{\text{Length of resistance arm}}$$

Question 1

Which of the following best describes the structure of ATP (adenosine triphosphate)?

Accepted Answer

Adenine, ribose, and three phosphate groups

Question 2

During the first 15 seconds of intense muscle activity, which energy system provides the majority of ATP?

Accepted Answer

Creatine phosphate system

Question 3

Which of the following equations correctly represents the reaction catalyzed by creatine kinase in muscle cells?

Accepted Answer

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

Question 4

Which muscle fiber type is most resistant to fatigue and is primarily used for maintaining posture?

Accepted Answer

Slow oxidative fibers

Question 5

A sprinter is most likely to have a higher proportion of which muscle fiber type in their leg muscles?

Accepted Answer

Fast glycolytic fibers

Question 6

Which of the following best explains why lactic acid accumulates in muscle during intense exercise?

Accepted Answer

Aerobic respiration is unable to keep up with ATP demand, so anaerobic glycolysis produces pyruvate, which is converted to lactic acid

Question 7

Which of the following is a correct formula for calculating mechanical advantage (MA) in a lever system?

Accepted Answer

$$\mathrm{MA} = \frac{	ext{Length of effort arm}}{	ext{Length of resistance arm}}$$

Question 8

Which of the following scenarios describes an isometric muscle contraction?

Accepted Answer

Holding a heavy box stationary without moving it

Question 9

What is the primary source of glucose for muscle cell respiration during prolonged exercise?

Accepted Answer

Glycogen stored in muscle and liver

Question 10

Which of the following best describes the role of myoglobin in muscle cells?

Accepted Answer

Stores oxygen for use during aerobic respiration

Question 11

A person is performing a biceps curl and slowly lowers the weight back down. Which type of contraction is occurring in the biceps muscle?

Accepted Answer

Isotonic eccentric contraction

Question 12

Which of the following is a characteristic of a third-class lever in the human body?

Accepted Answer

Effort is applied between the fulcrum and the resistance

Question 13

Which of the following is a likely cause of muscle fatigue during prolonged, intense exercise?

Accepted Answer

Depletion of glycogen stores

Question 14

Which muscle fiber type would be most beneficial for a marathon runner and why?

Accepted Answer

Slow oxidative fibers, because they resist fatigue and use aerobic respiration

Question 15

Which of the following best explains why a muscle can continue to contract for several minutes during moderate exercise?

Accepted Answer

Aerobic respiration provides a continuous supply of ATP as long as oxygen and glucose are available

Question 16

After intense exercise, why does the body experience 'oxygen debt'?

Accepted Answer

To metabolize lactic acid and replenish ATP, creatine phosphate, glycogen, and oxygen stores

Question 17

Which of the following best describes the effect of a mechanical advantage less than 1 in a lever system?

Accepted Answer

The lever increases speed but decreases force

Question 18

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

Accepted Answer

Production of 2 ATP per glucose and formation of lactic acid

Question 19

Which of the following training adaptations would you expect in the muscles of an endurance athlete?

Accepted Answer

Increased mitochondria, glycogen, and blood vessels in slow fibers

Question 20

Which of the following statements about motor units is correct?

Accepted Answer

Each motor unit contains only one type of muscle fiber

Muscle Metabolism and Mechanics: Energy, Fiber Types, and Levers

Study Guide - Practice Questions