Cytoskeleton

These flashcards cover key vocabulary and concepts related to the cytoskeleton and actin dynamics essential for understanding cell structure and function.

Cytoskeleton

A dynamic and complex network of protein filaments that extend throughout the cell, allowing for various cellular functions.

Microfilaments

Filamentous actin (F-actin) used for membrane motility, structure movement, and transport within the cytoplasm.

Actin

A protein that polymerizes into microfilaments, crucial for maintaining cell shape and motility.

Treadmilling

The dynamic process where actin filaments have asymmetrical growth and dissociation rates at their two ends, maintaining filament length while undergoing turnover.

Nucleation phase

The rate-limiting step in microfilament assembly where seed proteins like formin or Arp2/3 facilitate the formation of small actin oligomers.

Profilin

An actin-binding protein that enhances the polymerization rates of actin filaments.

Thymosin b4

A negative regulator of actin polymerization that decreases the build-up of actin filaments.

Rigor mortis

The condition post-mortem where ATP depletion leads to muscle stiffness due to myosin heads being unable to dissociate from actin filaments.

Myosin

Motor proteins that bind to actin and facilitate muscle contraction and cellular transport through a power stroke mechanism.

Critical Concentration

The equilibrium point at which the rates of actin filament growth and shrinkage are balanced.

Actin-Binding Proteins

Proteins that regulate the dynamics of actin filament assembly, stability, and function.

Endocytosis

The process by which cells engulf external substances, facilitated by actin filaments pushing or pulling the membrane.