the sarcomere

what is inside of microfibral

microfilaments

myosin

thick filaments

actin

thin filaments

what do thick and thin filaments do that causes muscle contraction

slide on eachother

Tropomyosin

Band covering myosin binding site on actin

troponin

Moves tropomyosin out of the way exposing myosin binding site on actin

sarcomere

tiny unit inside a muscle that makes the muscle shorten and contract

sarcomere parts

z disk, A band, i band, actin, myosin, m line, h zone

z disk

“wall” at each end of a sarcomere. holds the thin filaments in place

a band

dark part of the sarcomere. where myosin is, where actin and myosin overlap.

i band

light part of the sarcomere, only has actin no myosin.

m line

middle of the sarcomere holds thick myosin filaments in place.

actin function

gets pulled by myosin to make the muscle shorten

myosin function

grabs actin and pulls it, causing muscle contraction

h zone

area in middle of the A band. only has myosin (no actin) when muscle is relaxed.