Muscels & sliding filament Flashcards
3 types of muscle
Cardiac
Smooth
skeletal
Cardiac tissue
One nucleus per fibre
inter located discs
stituations
Involuntary
Smooth tissue
One nucleus per fibre
wider
digestive
artery
veins
Skeletal muscle
Bicep tricep
action potential can contract
mutinucliated
what is sarcomere?
Has a protein called actin (thin filaments). Another protein called myosin (thick filaments).
What are inside muscle tissue is?
Inside muscle tissue there are myofibrils (many myofibrils make up sarcomere).
Process of sliding filament model
Z-line & actin filaments attach.
Thick filaments (myosin) held together by accessory protein in this area called M line. When contracted the actin and myosin slide past eachother.
Actin are pulled by the myosin and they overlap, Z-lines are moved closer together.
Myosin and ATP
Myelin head binds to ATP - hydrolysed ATP- which results in ADP+P which both still bound to myosin head.
But the myosin head can now bind to actin which is called a cross-bridge.
Myosin head then performs a power stroke which release ADP+P.
A new ATP then binds to myosin and that attaches myosin from actin
What is a power stroke
A power stroke means thin filament (actin) slide towards sarcomere (the centre).
ATP=
ATP= cross bridge breaker
What happens when a neurone stimulates a muscle?
It can trigger a release of calcium.
The ca2+ ions bind to the troponin.
The troponin changes & this lets the tropomyosin move off the myosin and now myosin can bind.
Tropomyosin
Actin has tropomyosin on it- protein -that blocks the myosin bonding sites on the actin.
What does troponin do and what is it
and what does it do
It is a protein and it stops myosin binding this means muscle cannot contract.
