Question 1

Which of the following statements best describes the difference between prokaryotic and eukaryotic cells?

Accepted Answer

Eukaryotic cells have a nucleus surrounded by a membrane, whereas prokaryotic cells lack a true nucleus.

Question 2

Which component of the plasma membrane is primarily responsible for its amphipathic nature?

Accepted Answer

Phospholipids

Question 3

The fluid mosaic model of the plasma membrane suggests that:

Accepted Answer

Phospholipids and proteins can move laterally within the layer, creating a dynamic and flexible structure.

Question 4

Which experimental technique is used to measure the lateral movement of membrane components, such as phospholipids and proteins?

Accepted Answer

Fluorescence Recovery After Photobleaching (FRAP)

Question 5

Cholesterol plays a crucial role in animal cell membranes by:

Accepted Answer

Stabilizing membrane fluidity across temperature changes

Question 6

Which of the following best describes an integral membrane protein?

Accepted Answer

A protein that spans the lipid bilayer and has both hydrophobic and hydrophilic regions

Question 7

A phospholipid molecule in the plasma membrane has:

Accepted Answer

Two hydrophobic fatty acid tails and a hydrophilic phosphate head

Question 8

Which of the following equations best represents the calculation of membrane surface area for a spherical cell with radius $$r$$?

Accepted Answer

$$A = 4 \pi r^2$

Question 9

Peripheral membrane proteins are most likely to be found:

Accepted Answer

Attached to the surface of the membrane via interactions with integral proteins or phospholipid heads

Question 10

Which of the following is NOT a function of the plasma membrane?

Accepted Answer

Synthesizing proteins for cellular use

Question 11

A mutation causes a cell to produce phospholipids with two saturated fatty acid tails. What is the most likely effect on the plasma membrane?

Accepted Answer

The membrane will become less fluid and more rigid.

Question 12

Which of the following best explains why phospholipids spontaneously form bilayers in aqueous environments?

Accepted Answer

Their amphipathic nature causes hydrophobic tails to avoid water and hydrophilic heads to interact with water.

Question 13

Which of the following is a real-world example of membrane protein function in human health?

Accepted Answer

HIV infects cells by binding to specific membrane proteins such as CD4 and CCR5.

Question 14

Which of the following statements about the orientation of membrane components during biosynthesis is correct?

Accepted Answer

The orientation of membrane components is determined by the endomembrane system and vesicle fusion.

Question 15

Which of the following best describes the role of glycoproteins on the surface of red blood cells?

Accepted Answer

They serve as recognition molecules for cell-cell interactions.

Question 16

A scientist uses FRAP to study membrane protein mobility. After photobleaching a region, fluorescence returns slowly. What does this indicate about the membrane?

Accepted Answer

Membrane proteins are relatively immobile or restricted in movement.

Question 17

Which of the following is a correct application of the fluid mosaic model to explain how SARS-CoV-2 infects human cells?

Accepted Answer

The virus hijacks specific membrane proteins to gain entry into the cell.

Question 18

Which of the following is true regarding the asymmetrical distribution of phospholipids in animal plasma membranes?

Accepted Answer

Certain phospholipids, such as phosphatidylserine, are localized to specific leaflets and play roles in protein anchoring.

Question 19

Which of the following best describes the amphipathic nature of a transmembrane protein?

Accepted Answer

It has hydrophobic regions exposed to the lipid bilayer and hydrophilic regions exposed to the aqueous environment.

Single Cell Dynamics and Membrane Structure: Study Notes for General Biology

Guida di studio - Domande di pratica

Study guide - Flashcard