Muscle Flashcards
voluntary muscle
striated with fibers composed of repeating units of light and dark bands. fibers are surrounded by a membrane called sacrolemma
- sarcoplasma: liquid with ATP, glycogen and phosphocreatine
muscle fiber structure
striated: repeated light and dark bands
- composed of myofibrils in parallel arrangement
myofibril structure
sarcomere is the repeating unit
A band is dark
I band is light with a dark Z line in the middle
H zone is less dark region of A band with dark M line
HAM and
Z
see the diagram for the muscle
plz
where are the filaments found
- thick filaments found in H zone of A band
- thin filaments are found in I band
- both thick and thin found in the A band
thick and thin filament arrangement
each thick has 6 thin
contraction
length of thick and thin filaments don’t change
- length of sarcomere changes, more overlap during contraction
- H and I band decrease
proteins of th9ick and thin filaments
thick filaments have myosin
thin has actin, tropomyosin, troponin c
myosin
- spontaneously forms filaments in solution, is an ATPase, binds to actin
- has two large chains (200,000) with filament
- 4 light chains
- one glob portion with atpase activity
szent gyorgyi experiment
cleaved myosin with trypsin so you know the filaments are muscle fibers and the glob is atpase
actin
forms double stranded helix of g actin monomers
- thin
- associated with tropomyosin and is helix
role of atp
actin and myosin are separated by atp
- see the card structure
- slow release
troponin c
thin filament
0 binds ca
- tropomyosin forms the backbone of the actin filaments
titin
protein that spans 1/2 structure from z to m line
resting muscle
- has potential difference across membrane
- nerve impulse causes depolarization
- ca is stored in sarcoplasmic reticuluim
- ca binds ot troponin causes change in thin filaments to actin –> can bind
- ca is pumped back in
- ca dependent atpase??
