Sarcomere Organization
What is the functional unit of a muscle fiber
sarcomere
what links the myosin filaments together
m-line
does the Z-line move closer together or move farther apart
closer together
myosin heads of thick filaments bind to active sites on thin filaments
attach
why does a sarcomere appear banded
due to the arrangement of the thick and thin filaments
what links the actin filaments together at the end of the sarcomere
z-line
a theory that explains the physical changes that occur during contraction
sliding filament theory
myosin head pivot toward the m-line, pulling the actin filament toward the center of the sarcomere
pivot-pull
how are sarcomeres lined up
side to side
where actin filaments pass between the myosin filaments
zone of overlap
does the H-band get smaller or larger
smaller
cross bridge detaches and returns to normal position
release
includes the M-line, the H-band, and the zone of overlap
A-band
the area containing the thick filaments
H-band
does the I-band get smaller or larger
smaller
cycle is repeated
(true or false)
true
the are containing only thin filaments
I-band
larger
each time a cross bridge detaches, what is broken down
an ATP molecule