Cell Motility and Muscle Contraction Review

These flashcards cover key vocabulary and concepts related to cell motility and muscle contraction, helping students prepare for their exam.

Cell Motility

The ability of cells to move and position themselves.

Cilia

Short, numerous hair-like structures involved in cell movement.

Flagella

Long, whip-like structures used for mobility in cells.

Chemotaxis

Directional movement of organisms in response to a chemical stimulus.

Amoeboid movement

A type of movement characterized by the use of pseudopodia.

Kinesin

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

Dynein

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

Microtubules

Cylindrical structures that provide structural support and transport within cells.

Intraflagellar Transport

Mechanism by which kinesin and dynein move proteins along cilia and flagella.

Actin Filaments

Polymers of actin proteins that play essential roles in cell motility.

Myosins

Motor proteins that interact with actin filaments for muscle contraction.

Sarcomere

The basic contractile unit of striated muscle tissue.

Tropomyosin

A protein that regulates actin-myosin interactions in muscle contraction.

Troponin

A protein complex that, in conjunction with tropomyosin, regulates muscle contraction.

ATP Hydrolysis

Process by which ATP is broken down to release energy for cellular functions.

Muscle Contraction

The process enabling muscle fibers to shorten and generate force.

Cytoplasmic Dynein

A motor protein responsible for retrograde transport within cells.

Myofibrils

Contractile threads found in striated muscle cells comprised of sarcomeres.

Mitochondria

Organelles responsible for ATP production within muscle cells during contraction.

Cross-bridge cycling

The repetitive process of myosin heads binding to actin filaments in muscle contraction.

Sliding-filament model

Theory describing how muscle fibers contract by sliding thick and thin filaments past each other.

Z disk

The boundary structure of each sarcomere where actin filaments are anchored.

Calmodulin

A protein that binds calcium and regulates various cellular functions.

Nexin Links

Structural components that connect neighboring microtubules in cilia and flagella.

Myomesin

A protein that helps organize thick filaments within the sarcomere.

CapZ

A protein that caps the plus end of actin filaments to regulate their length.

Tropomodulin

A capping protein that stabilizes the minus end of actin filaments.

Retrograde Transport

The movement of vesicles toward the cell body along microtubules.

Muscle Fiber Types

Different categories of muscle cells based on speed and strength of contraction.

Calcium Ions (Ca2+)

Ions that play a critical role in initiating muscle contraction.

Sarcoplasmic Reticulum (SR)

The specialized endoplasmic reticulum that stores calcium ions in muscle cells.

T-tubules

Invaginations of the plasma membrane that facilitate transmission of action potentials in muscle cells.

Heavy Chain (Dynein)

The part of dynein that binds to the microtubule.

Motor Proteins

Proteins that convert chemical energy into mechanical work for movement.

Motor Domains

Regions of motor proteins responsible for binding and walking along filaments.

Situs Inversus

A condition in which internal organs are reversed from their normal positions.

Actin-Binding Site

The region on myosin that binds to actin filaments during contraction.

Power Stroke

The force-generating step of myosin heads during muscle contraction.

ATP-dependent Mechanism

Process whereby motor protein function relies on ATP hydrolysis for energy.

Sarcomeric Structures

Components of the sarcomere that include actin, myosin, and regulatory proteins.

Sliding Mechanism

The action where thick and thin filaments slide past one another during contraction.

Dynamic Instability

The rapid growth and shrinkage of microtubules.

Filopodia

Thin, finger-like projections from the cell that aid in movement.

Lamellipodia

Broad, sheet-like extensions of the cell membrane involved in cell motility.

Microvilli

Small, finger-like projections that increase the surface area of cells.

Cell Cortex

The dense network of filaments just beneath the plasma membrane.

Muscle Contraction Regulation

The process by which muscles control their contraction and relaxation.

G-Actin

Globular actin monomers that polymerize to form F-actin filaments.

F-Actin

Filamentous actin, a polymerized form of G-actin.

Contractile Proteins

Proteins that are involved in muscle contraction, primarily actin and myosin.

Enzymatic Activity

The ability of enzymes to catalyze biochemical reactions.

Arginine in Muscle

An amino acid that may play roles in muscle metabolism and blood flow regulation.