$$\text{ADP} + \text{CP} \xrightarrow{\text{creatine kinase}} \text{ATP} + \text{creatine}$$

Question 1

Which event directly triggers the release of calcium ions from the sarcoplasmic reticulum during skeletal muscle contraction?

Accepted Answer

Depolarization of the T-tubule membrane

Question 2

Botulinum toxin (BoTox) causes muscle paralysis by which mechanism?

Accepted Answer

Preventing presynaptic release of acetylcholine at the neuromuscular junction

Question 3

During the contraction cycle, what is the role of ATP in the cross-bridge cycle?

Accepted Answer

ATP hydrolysis energizes the myosin head for attachment to actin

Question 4

Which of the following best describes the effect of curare on skeletal muscle contraction?

Accepted Answer

Curare binds to acetylcholine receptors, preventing muscle activation

Question 5

Which equation represents the immediate ATP regeneration in skeletal muscle using creatine phosphate?

Accepted Answer

$$	ext{ADP} + 	ext{CP} \xrightarrow{	ext{creatine kinase}} 	ext{ATP} + 	ext{creatine}$$

Question 6

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

Accepted Answer

Activating acetylcholine receptors

Question 7

A patient is given a drug that inhibits acetylcholinesterase. What is the most likely effect on skeletal muscle contraction?

Accepted Answer

Muscle contraction will be prolonged due to continued stimulation by acetylcholine

Question 8

During muscle relaxation, which event occurs LAST?

Accepted Answer

Troponin shifts tropomyosin back over the myosin binding sites

Question 9

Which of the following is a product of anaerobic glycolysis in skeletal muscle?

Accepted Answer

Pyruvate and lactic acid

Question 10

Which process is responsible for the restoration of ion concentrations and blood pH after intense exercise?

Accepted Answer

Excess post-exercise oxygen consumption (EPOC)

Question 11

Which of the following best describes the sliding filament theory?

Accepted Answer

Actin filaments slide past myosin filaments, shortening the sarcomere

Question 12

Which of the following is required for aerobic cellular respiration in skeletal muscle?

Accepted Answer

Oxygen

Question 13

A person takes massive doses of creatine supplements. Which of the following is a likely outcome?

Accepted Answer

Excess creatine is excreted in the urine

Question 14

Which of the following events occurs FIRST during excitation-contraction coupling?

Accepted Answer

Action potential travels down the T-tubules

Question 15

Which of the following is a direct effect of acetylcholine binding to its receptor on the motor end plate?

Accepted Answer

Opening of ligand-gated Na+ channels

Question 16

Which of the following is TRUE regarding the role of troponin in muscle contraction?

Accepted Answer

Troponin binds calcium, causing tropomyosin to shift and expose actin binding sites

Question 17

Which of the following is a consequence of lactic acid build-up in skeletal muscle during intense exercise?

Accepted Answer

Decrease in blood pH

Question 18

Which of the following is the correct sequence of events in the cross-bridge cycle?

Accepted Answer

ATP hydrolysis energizes myosin, myosin binds actin, power stroke, ATP binds myosin causing detachment

Question 19

Which of the following is a clinical application of botulinum toxin (BoTox)?

Accepted Answer

Treatment of muscle spasticity by causing temporary paralysis

Question 20

Which of the following is a source of oxygen for aerobic cellular respiration in skeletal muscle?

Accepted Answer

Myoglobin within muscle fibers

Skeletal Muscle Contraction and Energy Sources: Study Guide

스터디 가이드 - 연습 문제