Q: Motor proteins utilize energy from ATP hydrolysis to move along cytoskeletal tracks. Which of the following equations best represents the hydrolysis of ATP?

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

Question 1

Which cytoskeletal component is primarily responsible for providing cell shape, movement, and transport, and serves as tracks for motor proteins such as kinesin and dynein?

Accepted Answer

Microtubules

Question 2

Motor proteins utilize energy from ATP hydrolysis to move along cytoskeletal tracks. Which of the following equations best represents the hydrolysis of ATP?

Accepted Answer

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

Question 3

Kinesin and dynein are motor proteins that move along microtubules. Which direction does kinesin typically move relative to the microtubule polarity?

Accepted Answer

Towards the plus end

Question 4

A scientist observes vesicle transport in a neuron and notes that vesicles move from the cell body towards the axon terminal. Which motor protein is most likely responsible for this movement?

Accepted Answer

Kinesin

Question 5

Dynein moves cargo in the opposite direction to kinesin. Which of the following best describes dynein's direction of movement?

Accepted Answer

Towards the minus end of microtubules

Question 6

Which of the following statements about motor proteins is TRUE?

Accepted Answer

Kinesin moves towards the plus end, while dynein moves towards the minus end

Question 7

A mutation in the ATP-binding site of kinesin is most likely to affect which aspect of its function?

Accepted Answer

Its ability to hydrolyze ATP and generate movement

Question 8

Which of the following experimental results would best support the hypothesis that a purified protein is NOT myosin?

Accepted Answer

The protein was isolated by adding then purifying actin microfilaments that it was bound to.

Question 9

Which of the following is NOT a function of cytoskeletal motor proteins?

Accepted Answer

DNA replication

Question 10

A researcher adds a drug that inhibits ATP hydrolysis in a cell. What is the most likely effect on motor protein function?

Accepted Answer

Motor proteins will be unable to move cargo along cytoskeletal tracks

Question 11

Which of the following best explains why motor proteins are essential for intracellular transport?

Accepted Answer

They hydrolyze ATP to generate force for movement along cytoskeletal tracks

Question 12

A cell is observed to have defective dynein function. Which of the following cellular processes is most likely to be impaired?

Accepted Answer

Transport of vesicles towards the cell center

Question 13

Which of the following statements about the directionality of motor proteins is correct?

Accepted Answer

Kinesin moves towards the plus end and dynein towards the minus end of microtubules

Question 14

Which of the following would be the best evidence that a protein is a microtubule-based motor protein rather than an actin-based motor protein?

Accepted Answer

The protein binds to microtubules and moves cargo along them

Question 15

A cell biologist wants to track the movement of mitochondria in a living cell. Which motor protein should they focus on if the mitochondria are moving towards the cell periphery?

Accepted Answer

Kinesin

Question 16

Which of the following is a distinguishing feature of kinesin compared to dynein?

Accepted Answer

Kinesin moves towards the plus end of microtubules

Question 17

A mutation causes a motor protein to lose its ability to bind to microtubules. Which process would be most directly affected?

Accepted Answer

Transport of vesicles along microtubules

Question 18

Which of the following best describes the role of ATP in motor protein function?

Accepted Answer

ATP hydrolysis provides energy for conformational changes that result in movement

Question 19

A scientist isolates a protein by purifying actin microfilaments that it was bound to. Which type of motor protein is this most likely to be?

Accepted Answer

Myosin

Question 20

Which of the following scenarios best illustrates the application of motor protein function in a medical context?

Accepted Answer

Defective kinesin leads to impaired axonal transport, contributing to neurodegenerative diseases

Motor Proteins and Cytoskeleton: Mechanisms of Cellular Movement

Study Guide - Practice Questions

Study Guide - Flashcards