Ch9 pt 2 Regulated Molecular Motors in Skeletal Muscle

Flashcards summarizing key concepts about the structure and function of muscle fibers, sarcomeres, myofibrils, and related pathologies.

What are myofibrils in skeletal muscle fibers?

Myofibrils are rod-like structures that run parallel to the length of the muscle fiber and are made of chains of sarcomeres linked end to end.

What is the function of the sarcoplasmic reticulum?

The sarcoplasmic reticulum regulates intracellular calcium levels, storing and releasing calcium on demand during muscle contraction.

What is the sliding filament model of muscle contraction?

The sliding filament model describes how thin filaments slide past thick filaments, causing muscle contraction without changing the length of either filament.

What is the diameter range of skeletal muscle fibers?

Skeletal muscle fibers typically have a diameter ranging from 10 to 100 micrometers.

What is the functional unit of a muscle fiber?

The functional unit of a muscle fiber is the sarcomere, which is the area between two Z discs.

What structure anchors the thin filaments in a sarcomere?

The Z disc anchors the thin filaments in a sarcomere.

What two types of contractile myofilaments are found in a sarcomere?

The two types of contractile myofilaments are thick filaments made of myosin and thin filaments made of actin.

What role does myoglobin play in muscle cells?

Myoglobin stores oxygen in muscle cells and releases it during activity for ATP production.

How are the T tubules involved in muscle contraction?

T tubules allow the rapid transmission of electrical impulses to the deepest parts of the muscle fiber, triggering calcium release from the sarcoplasmic reticulum.

What is Duchenne muscular dystrophy?

Duchenne muscular dystrophy (DMD) is a genetic disorder that results in muscle degeneration and weakness due to a defective gene for dystrophin.