Cytoskeleton & Cell Movement

This set of flashcards covers key terminology, structures, functions, and clinical significance related to the cytoskeleton and cell movement.

Microfilaments (Actin)

Protein filaments of 7 nm that consist of two intertwined strands of globular G-actin that polymerize into F-actin, maintaining cell shape, muscle contraction, cell motility, and cytoplasmic streaming.

Intermediate Filaments (IFs)

Variety of proteins (e.g., keratins, vimentin, lamins) of 8-12 nm that provide structural and mechanical strength to cells and tissues, and lack dynamic movement.

Microtubules

Hollow tubes of 25 nm constructed from 13 columns of tubulin dimers (α-tubulin and β-tubulin), which are dynamic structures that grow and shrink.

Kinesin

A motor protein that mediates anterograde transport towards the plus end of microtubules, moving cargo towards the cell periphery or synapses.

Dynein

A motor protein that mediates retrograde transport towards the minus end of microtubules, moving cargo back towards the cell body.

Myosin I

A protein involved in vesicle transport that attaches to organelles and walks along F-actin filaments.

Myosin II

The conventional myosin responsible for muscle contraction.

9 + 2 microtubule arrangement

A structure found in cilia and flagella consisting of a ring of nine microtubule doublets surrounding two central microtubules.

9 + 0 microtubule arrangement

A structure found in centrioles and basal bodies consisting of a ring of nine microtubule triplets with no central microtubules.

Cilia and Flagella movement

Movement driven by axonemal dynein causing microtubule doublets to slide against each other, anchored to create a bending motion.

Tight Junctions

Cell junctions that form a water-tight seal between cells to prevent fluid leakage.

Desmosomes

Cell junctions that act like rivets, anchoring cells together using sturdy cytokeratin fibers.

Gap Junctions

Cell junctions that provide cytoplasmic channels between cells for the movement of ions and small molecules.

Duchenne Muscular Dystrophy (DMD)

An X-linked disorder caused by a mutation in the dystrophin gene, leading to instability and damage of muscle cells during contraction.

Cytoskeleton

A network of fibers in the cell that provides structural support, facilitates movement, and organizes cellular components.