$\text{Kinesin} + \text{ATP} \rightarrow \text{Kinesin-ATP} \rightarrow \text{Kinesin} + \text{ADP} + \text{P}_i$

$\text{Protein-ER signal sequence} \xrightarrow{\text{signal peptidase}} \text{Protein} + \text{ER signal sequence}$

Question 1

Which of the following best describes the function of the nuclear envelope in eukaryotic cells?

Accepted Answer

It separates the nucleus from the cytosol and regulates transport through nuclear pores.

Question 2

A protein destined for secretion from a cell must first contain a specific sequence of amino acids. What is this sequence called?

Accepted Answer

ER signal sequence

Question 3

During the secretory pathway, which organelle is responsible for the stepwise processing and modification of proteins?

Accepted Answer

Golgi apparatus

Question 4

Which process allows vesicles to deliver their contents to the plasma membrane for secretion?

Accepted Answer

Exocytosis

Question 5

In a pulse-chase experiment, what is the purpose of the 'chase' phase?

Accepted Answer

To track the movement of previously labeled proteins by replacing radioactive amino acids with normal ones.

Question 6

Which cytoskeletal filament is primarily responsible for moving chromosomes during cell division?

Accepted Answer

Microtubules

Question 7

A protein is synthesized by a ribosome and contains an ER signal sequence. What is the next step in its journey?

Accepted Answer

It binds to a signal recognition particle (SRP), which halts synthesis.

Question 8

Which of the following equations best represents the energy requirement for kinesin movement along microtubules?

Accepted Answer

$	ext{Kinesin} + 	ext{ATP} ightarrow 	ext{Kinesin-ATP} ightarrow 	ext{Kinesin} + 	ext{ADP} + 	ext{P}_i$

Question 9

Which cytoskeletal component anchors the nucleus and other organelles in place?

Accepted Answer

Intermediate filaments

Question 10

What is the main function of actin-myosin interactions in animal cells?

Accepted Answer

To cause cell movement and cytokinesis

Question 11

Which mechanism is used by cells to recycle damaged organelles?

Accepted Answer

Autophagy

Question 12

A protein is tagged in the Golgi apparatus for delivery to the lysosome. What is the most likely fate of this protein?

Accepted Answer

It will be delivered to the lysosome for degradation or recycling.

Question 13

Which of the following best explains why vesicles can fuse with membranes during exocytosis?

Accepted Answer

Membranes are fluid, allowing vesicles to pinch off and fuse.

Question 14

Which equation best represents the removal of the ER signal sequence during protein synthesis?

Accepted Answer

$	ext{Protein-ER signal sequence} \xrightarrow{	ext{signal peptidase}} 	ext{Protein} + 	ext{ER signal sequence}$

Question 15

Which cytoskeletal filament provides tracks for intracellular transport, such as vesicle movement?

Accepted Answer

Microtubules

Question 16

A mutation prevents the addition of carbohydrate groups to proteins in the rough ER. Which cellular process would be most affected?

Accepted Answer

Protein sorting in the Golgi apparatus

Question 17

Which of the following is NOT a function of the endomembrane system?

Accepted Answer

Synthesizing ATP for cellular energy

Question 18

During receptor-mediated endocytosis, what is the fate of the receptors after delivering their cargo?

Accepted Answer

They are recycled back to the plasma membrane.

Question 19

Which cytoskeletal filament is most important for muscle contraction and cell crawling?

Accepted Answer

Actin filaments

Ch. 7 part 2 (7.4-7.6)

Study Guide - Practice Questions