Lab2 - Q1-4 - Discussion Questions Lab 2 Skeletal Muscle...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Discussion Questions Lab 2 Skeletal Muscle Mechanics 1. Skeletal muscle fiber is a muscle cell that contains a bundle of myofibrils. Myofibrils are intracellular contractile structures made up of thick (myosin) filaments and thin (actin) filaments. Diagram see page 258 and 263 Cross-bridging between actin and myosin causes muscle contraction within each sarcomere. Upon action potential that travels across the muscle membrane and down the transverse tubules, Ca is released from the Sarcoplasmic reticulum and. Cytosolic Ca binds to troponin which pulls tropomyosin away from the myosin binding site on the thin filament. This allows the myosin heads to bind to the thin filament pulling the Zlines together. The myosin head uses the energy from ATP hydrolysis to perform power stroke. With the binding of fresh ATP the myosin head detaches and muscle relaxes. The bound ATP is hydrolyzed to ADP and the myosin head is cocked and ready for more cross-bridging and power strokes as soon as Ca removes troponin-tropomyosin complex from binding site on
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 2

Lab2 - Q1-4 - Discussion Questions Lab 2 Skeletal Muscle...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online