Q.89 Desmosomes are
(A) intermediate filament–based cell adhesion complexes.
(B) protein synthesizing macromolecular complexes.
(C) subcellular organelles.
(D) DNA–protein complexes.

Desmosomes are intermediate filament-based cell adhesion complexes that anchor adjacent cells together for mechanical strength. The correct answer to the question is option (A).

Option Analysis

Desmosomes function as spot-like junctions linking keratin intermediate filaments across cells, essential in tissues like skin and heart under stress.​

• (A) Intermediate filament-based cell adhesion complexes: Matches exactly, as desmosomes couple cadherins (desmogleins, desmocollins) to intermediate filaments via plaque proteins like desmoplakin, plakoglobin, and plakophilins.​

• (B) Protein synthesizing macromolecular complexes: Incorrect; these describe ribosomes, not desmosomes, which focus on adhesion, not synthesis.​

• (C) Subcellular organelles: Wrong; desmosomes are plasma membrane junctions, not membrane-bound organelles like mitochondria.​

• (D) DNA-protein complexes: No; these refer to chromatin, unrelated to desmosomes’ cytoskeletal role.​

Desmosomes intermediate filament-based cell adhesion complexes provide robust intercellular links vital for tissue integrity. These junctions dominate in high-stress epithelia, making them key for CSIR NET life sciences preparation.​

Structure Details

Desmosomes feature an extracellular core (desmoglea) of cadherin interactions, plus cytoplasmic plaques tethering keratin intermediate filaments. Plakoglobin and desmoplakin anchor filaments, enabling force distribution.​

Key Functions

They resist shear stress in epidermis and myocardium by integrating adhesion with cytoskeletal networks. Mutations disrupt integrity, causing diseases like pemphigus.​

Exam Relevance

For CSIR NET, recognize desmosomes as (A) over flawed options like organelles or DNA complexes. They differ from actin-linked adherens junctions.​