Cytoskeleton and Muscle Contraction

These flashcards cover key terms and concepts related to the cytoskeleton, muscle contraction, and HIV trafficking as outlined in the provided lecture notes.

Cytoskeleton

A network of interconnected filaments and tubules in a cell that plays roles in its shape, movement, and division.

Microfilaments

Filaments primarily composed of actin that are involved in muscle contraction, cell movement, and maintaining cell shape.

Microtubules

The largest cytoskeletal structures composed of tubulin dimers that facilitate intracellular transport and maintain cell shape.

Motor Proteins

Proteins that convert chemical energy into mechanical work to move along the cytoskeletal elements.

Actin

The protein that serves as a building block for microfilaments; exists as globular G-actin and filamentous F-actin.

Treadmilling

A dynamic process in which actin filaments grow at one end while simultaneously shrinking at the other.

Myosin

A motor protein associated with microfilaments that facilitates muscle contraction through ATP hydrolysis.

Excitation-Contraction Coupling

The physiological process linking electrical stimulation of a muscle to the contraction mechanism.

Intermediate Filaments

Cytoskeletal components with a diameter of 8-12 nm that provide structural support but lack motor proteins.

Kinesin

A motor protein that transports cellular cargo toward the plus end of microtubules.

Dynein

A motor protein that transports cellular cargo toward the minus end of microtubules.

Dynamic Instability

The phenomenon where microtubules rapidly grow and shrink due to the addition and hydrolysis of GTP on tubulin dimers.

HIV Trafficking

The process through which HIV utilizes cytoskeletal components and motor proteins for replication and transport within host cells.

Cross Bridge Cycle

A series of steps during muscle contraction involving the binding and release of myosin to actin filaments.

Sarcoplasmic Reticulum

Specialized endoplasmic reticulum in muscle cells that regulates calcium ions for muscle contraction.