Actin / Myosin Flashcards
actin
A globular protein that forms actin filaments; found in thin filaments.
cardiac muscle
Striated muscle found in the heart.
creatine phosphate
A small organic molecule that can transfer a phosphate group to ATP.
excitation-contraction coupling
Contraction of a muscle fiber that results from motor neuron stimulation.
glycogen
A glucose polymer found in animals.
motor neuron
Neuron that regulates muscle contraction.
muscle fiber
An individual muscle cell.
myofibril
A bundle of myofilaments inside a striated muscle cell.
myofilament
Filaments involved in muscle contraction; includes thick and thin filaments.
myosin
The motor protein in the thick filament that binds actin and causes muscle contraction.
neuromuscular junction
Synapse between a motor neuron and a muscle fiber.
sarcomere
Repeating unit in myofibrils that gives skeletal muscle a striated appearance.
sarcoplasm
Cytoplasm of a muscle cell.
sarcoplasmic reticulum
A modified endoplasmic reticulum found in muscle cells that stores calcium ions.
skeletal muscle
Muscle attached to bones that is responsible for voluntary movement.
sliding filament model
Model that describes the movement of thick and thin filaments past each other during contractions.
smooth muscle
Involuntary, unstriated muscle surrounding hollow organs.
thick filament
Muscle fiber filament containing myosin.
thin filament
Muscle fiber filament containing actin.
transverse (T-) tubule
An infolding of the plasma membrane in muscle cells that makes close contact with the sarcoplasmic reticulum.
tropomyosin
Filamentous protein that is associated with actin; involved in regulation of muscle contraction.
troponin
Association of three regulatory proteins that control muscle contraction.
