Q: Which equation represents the Nernst potential for an ion across a membrane?

$E = \frac{RT}{zF} \ln \left( \frac{[\text{ion}]_{\text{outside}}}{[\text{ion}]_{\text{inside}}} \right)$

Question 1

Which of the following is a key difference between prokaryotic and eukaryotic cells?

Accepted Answer

Eukaryotic cells possess a nucleus and intracellular organelles, while prokaryotic cells do not.

Question 2

Which organelle is primarily responsible for protein synthesis in eukaryotic cells?

Accepted Answer

Ribosomes

Question 3

Which of the following best describes the function of the plasma membrane?

Accepted Answer

It regulates the movement of substances into and out of the cell.

Question 4

Which statement about membrane lipids is correct?

Accepted Answer

Phospholipids are the most abundant lipids in membranes.

Question 5

Which process is energetically unfavorable and requires the enzyme flippase?

Accepted Answer

Transverse diffusion (flip-flop) of lipids

Question 6

A cell is placed in a hypotonic solution. What will most likely happen to the cell?

Accepted Answer

The cell will swell as water enters by osmosis.

Question 7

Which equation best describes the rate of simple diffusion across a membrane?

Accepted Answer

$J = P 	imes (C_1 - C_2)$

Question 8

Which of the following best explains why cholesterol is important in membrane structure?

Accepted Answer

Cholesterol decreases membrane fluidity at high temperatures and increases it at low temperatures.

Question 9

Which type of transport requires energy input from the cell?

Accepted Answer

Active transport

Question 10

A sodium-potassium pump moves 3 Na$^+$ ions out of the cell and 2 K$^+$ ions into the cell per cycle. Which equation represents the net charge movement per cycle?

Accepted Answer

$+1$ net positive charge out of the cell

Question 11

Which of the following is a function of the endoplasmic reticulum (ER)?

Accepted Answer

Protein and lipid synthesis

Question 12

Which statement best describes the difference between direct and indirect active transport?

Accepted Answer

Direct active transport uses ATP directly, while indirect active transport uses the energy stored in ion gradients.

Question 13

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

Accepted Answer

Mitochondrion

Question 14

Which process is responsible for the fusion of a vesicle with the plasma membrane to release its contents outside the cell?

Accepted Answer

Exocytosis

Question 15

Which of the following best describes the role of SNARE proteins in vesicle trafficking?

Accepted Answer

They mediate the fusion of vesicles with target membranes.

Question 16

Which equation represents the Nernst potential for an ion across a membrane?

Accepted Answer

$E = \frac{RT}{zF} \ln \left( \frac{[	ext{ion}]_{	ext{outside}}}{[	ext{ion}]_{	ext{inside}}} ight)$

Question 17

Which of the following is true about action potentials in neurons?

Accepted Answer

Action potentials are all-or-none events that propagate without loss of amplitude.

Question 18

Which statement best describes the function of neurotransmitters at the synaptic cleft?

Accepted Answer

Neurotransmitters bind to specific receptor proteins on the postsynaptic cell, triggering further transmission of the signal.

Question 19

Which of the following best describes the effect of ligand binding to a G-protein coupled receptor?

Accepted Answer

It activates a G-protein, which then triggers a signaling cascade involving molecules such as cAMP or IP3.

Question 20

Which of the following is a real-world example of cellular signaling involving receptor kinases?

Accepted Answer

Insulin binding to its receptor, leading to phosphorylation and activation of downstream signaling molecules.

Cell Biology: Key Concepts and Processes

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