Question 1

Which of the following best describes the amphipathic nature of phospholipids in the cell membrane?

Accepted Answer

They have both hydrophilic and hydrophobic regions, allowing them to form bilayers in aqueous environments.

Question 2

Which experimental evidence was crucial in the development of the fluid mosaic model of the membrane?

Accepted Answer

Freeze-fracture electron microscopy revealed proteins embedded within the lipid bilayer.

Question 3

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

Accepted Answer

Increasing membrane permeability to small ions.

Question 4

Which of the following best explains why type O blood is considered the universal donor?

Accepted Answer

Type O blood lacks A and B antigens on the surface of erythrocytes, reducing the risk of immune reaction.

Question 5

Which of the following statements about lipid rafts is correct?

Accepted Answer

Lipid rafts are membrane microdomains enriched in cholesterol and sphingolipids.

Question 6

Which technique would you use to analyze the molecular weight of membrane proteins after denaturation?

Accepted Answer

SDS-PAGE

Question 7

A red blood cell is placed in a hypertonic solution. What will happen to the cell?

Accepted Answer

Water will leave the cell, causing it to shrink (crenate).

Question 8

Which of the following best describes the difference between primary and secondary active transport?

Accepted Answer

Primary active transport uses ATP directly, while secondary active transport uses the energy stored in an ion gradient.

Question 9

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

Accepted Answer

Synthesis of membrane-bound and secretory proteins.

Question 10

A protein contains a KDEL sequence and is found in the Golgi apparatus. What will happen to this protein?

Accepted Answer

It will be retrieved and returned to the endoplasmic reticulum.

Question 11

Which of the following is necessary for vesicle fusion with the target membrane?

Accepted Answer

Interaction between v-SNAREs on the vesicle and t-SNAREs on the target membrane.

Question 12

Why is the vesicle coat shed during vesicular transport?

Accepted Answer

To expose v-SNAREs for interaction with t-SNAREs, allowing vesicle fusion.

Question 13

Which of the following best describes the function of the γ-tubulin ring complex (γ-TuRC) in the centrosome?

Accepted Answer

It nucleates the assembly of new microtubules at the minus end.

Question 14

Which of the following statements about microfilaments is correct?

Accepted Answer

Microfilaments are polar structures composed of actin monomers.

Question 15

Which motor protein moves toward the plus end of microtubules and is responsible for anterograde transport?

Accepted Answer

Kinesin

Question 16

During muscle contraction, what happens to the sarcomere structure?

Accepted Answer

The Z discs move closer together as actin and myosin filaments slide past each other.

Question 17

Which of the following best describes the difference between carrier proteins and channel proteins?

Accepted Answer

Carrier proteins undergo conformational changes to transport molecules, while channel proteins form open pores.

Question 18

Which of the following is a function of the lysosome?

Accepted Answer

Degradation of macromolecules and cellular debris.

Question 19

Which of the following statements about intermediate filaments is correct?

Accepted Answer

They are nonpolar, provide mechanical strength, and do not have associated motor proteins.

Cell Membranes, Membrane Transport, Endomembrane System, and Cytoskeleton: Study Guide

Guida di studio - Domande di pratica