Q: Which of the following equations correctly represents the hydrolysis of ATP during muscle contraction?

$ \mathrm{ATP} + \mathrm{H}_2\mathrm{O} \rightarrow \mathrm{ADP} + \mathrm{P}_i + \text{energy} $

Question 1

Which of the following best describes the role of ATP in skeletal muscle contraction?

Accepted Answer

ATP hydrolysis provides the energy for the myosin head to perform the power stroke during contraction.

Question 2

A patient is unable to relax their skeletal muscles after contraction. Which of the following is the most likely explanation?

Accepted Answer

There is a lack of ATP available to detach myosin heads from actin.

Question 3

Which of the following correctly matches a muscle group with its primary action?

Accepted Answer

Gastrocnemius – plantar flexion of the foot

Question 4

During a biceps curl, which muscle acts as the antagonist?

Accepted Answer

Triceps brachii

Question 5

Which of the following best describes the difference between concentric and eccentric isotonic contractions?

Accepted Answer

Concentric contractions involve muscle shortening as it does work, while eccentric contractions involve muscle lengthening as it resists a load.

Question 6

A lever system in the human body is classified as a third-class lever if:

Accepted Answer

The effort is applied between the fulcrum and the load.

Question 7

Which of the following proteins binds calcium ions to initiate skeletal muscle contraction?

Accepted Answer

Troponin

Question 8

Which of the following best explains why cardiac muscle cannot undergo tetanus (sustained contraction)?

Accepted Answer

Cardiac muscle cells have a long refractory period due to prolonged calcium influx.

Question 9

A muscle fiber is observed to have striations, multiple peripheral nuclei, and voluntary control. Which type of muscle is this?

Accepted Answer

Skeletal muscle

Question 10

Which of the following best describes the function of the sarcoplasmic reticulum in skeletal muscle fibers?

Accepted Answer

It stores and releases calcium ions necessary for muscle contraction.

Question 11

A patient is given a drug that blocks acetylcholine receptors at the neuromuscular junction. What is the most likely effect?

Accepted Answer

Decreased muscle contraction

Question 12

Which of the following equations correctly represents the hydrolysis of ATP during muscle contraction?

Accepted Answer

$ \mathrm{ATP} + \mathrm{H}_2\mathrm{O} ightarrow \mathrm{ADP} + \mathrm{P}_i + 	ext{energy} $

Question 13

Which of the following is a function of the antagonist muscle during movement?

Accepted Answer

It opposes the action of the prime mover to control or slow the movement.

Question 14

Which of the following best describes the arrangement of the sarcomere during muscle contraction?

Accepted Answer

The I band and H zone both shorten, while the A band remains the same length.

Question 15

Which of the following muscles is correctly paired with its location?

Accepted Answer

Latissimus dorsi – lower back

Question 16

A person is performing a squat. Which muscle group is primarily responsible for extending the knee as they rise?

Accepted Answer

Quadriceps femoris

Question 17

Which of the following best explains how ATP is regenerated during intense, short-duration exercise (such as sprinting)?

Accepted Answer

By direct phosphorylation of ADP by creatine phosphate

Question 18

Which of the following statements about smooth muscle is correct?

Accepted Answer

Smooth muscle contraction is involuntary and not under conscious control.

Question 19

Which of the following best describes the function of synergist muscles?

Accepted Answer

They assist the prime mover by adding extra force or reducing undesirable movements.

Question 20

A patient presents with muscle weakness and is diagnosed with myasthenia gravis, an autoimmune disorder that targets acetylcholine receptors. Which step of muscle contraction is most directly affected?

Accepted Answer

Binding of acetylcholine to receptors on the motor end plate

Muscle Tissue and Muscular System: Structure, Function, and Physiology

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