explain cross bridge formation in hanson and huxley theory of muscle contraction
Answers
nerve fibres releases neurotransmitters acetylcholine at sarcolemma
sarcolemma gets polarized by influx of sodium
wave of depolarization excite triad via T tubule system through z-line
triad consists of tubulin protein plus two sarcoplasmic vesicles releases calcium plus two in sarcoplasm
calcium plus two binds to tpc and leads to un masking of active site of actin
head of crossbridge binds to active site ATP bytes to head of crossbridge myosin atps causes breakdown of ATP to liberate energy this energy helps in swing of cross bridge in contractions way out relaxation and other ATP molecule bytes and causes and attachment of crossbridge calcium Plus to get back in sarcoplasmic vesicle logout of calcium
Cross-bridge theory states that actin and myosin form a protein complex (classically called actomyosin) by attachment of myosin head on the actin filament, thereby forming a sort of cross-bridge between the two filaments.