Cell Junctions Quiz

Questions and Answers

Which type of cell junction prevents paracellular movement of solutes?

Gap junctions

Tight junctions (correct)

Desmosomes

Adherence junctions

What is the primary function of desmosomes?

Facilitating cell communication

Connecting cells to the basement membrane

Providing structural support (correct)

Preventing solute movement

What consequence does the loss of E-cadherin have?

Promotes cell adhesion

Promotes metastasis (correct)

Facilitates tissue repair

Strengthens tight junctions

Which proteins are associated with gap junctions?

<p>Connexons</p> Signup and view all the answers

What role do hemidesmosomes play in cell structure?

<p>Connecting keratin to the basement membrane</p> Signup and view all the answers

Study Notes

Cell Junctions

Tight Junctions (Zonula Occludens): Form a barrier that prevents the paracellular movement of solutes; made up of proteins claudins and occludins.
Adherens Junctions (Belt Desmosome, Zonula Adherens): Create a "belt" structure that connects the actin cytoskeletons of adjacent cells utilizing cadherins, which are calcium-dependent adhesion proteins. Loss of E-cadherin is associated with increased metastasis in cancers.
Desmosomes (Spot Desmosome, Macula Adherens): Provide structural support through interactions with intermediate filaments. In pemphigus vulgaris, autoantibodies target desmoglein 3 and sometimes desmoglein 1, disrupting desmosomal function.
Gap Junctions: Comprised of channel proteins called connexons that enable electrical and chemical communication between neighboring cells, facilitating synchronized cellular activities.
Hemidesmosomes: Anchor keratin in basal cells to the underlying basement membrane. In bullous pemphigoid, the presence of autoantibodies disrupts this connection, leading to skin blistering.
Integrins: These membrane proteins play a critical role in maintaining the integrity of the basolateral membrane by binding to extracellular matrix components such as collagen, laminin, and fibronectin, ensuring stable cell adhesion.

Description

Test your knowledge on various types of cell junctions, including tight junctions, adherence junctions, and desmosomes. This quiz will explore their structures, functions, and relevance in cellular adhesion. Perfect for students in cell biology or related fields.