Understanding Muscle Contraction

What is the basic unit of muscle contraction?

• muscle fiber

• myofibril

• actin

• sarcomere

Describe the role of calcium ions in muscle contraction.

• Calcium ions bind to troponin, enabling muscle contraction by exposing myosin-binding sites on actin.

• Calcium ions inhibit muscle contraction by blocking actin sites.

• Calcium ions are released from the mitochondria during muscle relaxation.

• Calcium ions are responsible for generating ATP in muscle cells.

What is the sliding filament theory?

• The sliding filament theory explains the process of nerve signal transmission.

• The sliding filament theory describes the mechanism of muscle contraction through the sliding of actin and myosin filaments.

• The sliding filament theory is a method for measuring muscle strength.

• The sliding filament theory describes the structure of muscle fibers.

How does ATP contribute to muscle contraction?

• ATP inhibits the binding of actin and myosin.

• ATP is only needed for muscle relaxation.

• ATP is essential for muscle contraction as it powers the interaction between actin and myosin.

• ATP is a waste product of muscle contraction.

What are the differences between isotonic and isometric contractions?

• Isotonic contractions are slower than isometric contractions, which are faster.

• Isotonic contractions involve no movement, while isometric contractions involve muscle shortening.

• Isotonic contractions are only performed with weights, while isometric contractions can be done without any resistance.

• Isotonic contractions involve movement and muscle shortening, while isometric contractions involve tension without movement.