The sliding Filament Theory

Descrição

A-level Year 13 - Applied Science FlashCards sobre The sliding Filament Theory , criado por Astrid Mifsud em 21-11-2017.
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Resumo de Recurso

Questão Responda
What happens to a contracting sarcomere? The I-band shrinks - pulling the Z-line and A-band together - The H-zone also shrinks
What is Troponin? Molecules that are bound to tropomyosin. Which contain calcium ion binding sites.
Where is Tropomyosin found? It wound around the actin
What is the first stage of the Sliding Filament Theory? Relaxed muscle - tropomyosin blocks the binding sites on the actin filaments. - prevents myosin and actin binding together, so contraction is impossible
What is the second stage of the Sliding Filament Theory? Nerve impulses stimulate the release of calcium ions - from the sarcoplasmic reticulum
What is the third stage of the Sliding Filament Theory? High concentrations - calcium ions bind to troponin. This causes the tropomyosin to change shape, exposing the actin binding sites
What is the forth stage of the Sliding Filament Theory? The activated myosin heads bind to the actin filament, producing tension in the muscle
What is the fifth stage of the Sliding Filament Theory? Binding to the actin causes myosin heads to change shape. Causing the whole filmanet to be pulled along the actin. - ADP is now released from myosin heads
What is the sixth stage of the Sliding Filament Theory? ATP binds to the myosin heads. This is broken down to produce ADP, Pi and energy. Energy allows the myosin heads to release actin and return to original state
What is the seventh stage of the Sliding Filament Theory? The cycle now repeats. - dragging the myosin filaments further along the actin - sarcomere will continue to contract if ATP is present
What is the eighth stage of the Sliding Filament Theory? Calcium is actively removed for the sarcoplasm when the muscle no longer stimulates the nerve. Tropomyosin returns to original state.
What is the ninth stage of the Sliding Filament Theory? Bridges are no longer formed between actin and myosin. With no force holding the fibres together, fibres are pulled apart by antagonistic muscle action