Skeletal muscle contraction Flashcards
1
Q
During muscle contraction
A
The I band disappears
- A band is the thick filament
- I band is the space in btwn the thick filaments
2
Q
Regulatory light chain (RLC)
A
Phosphorylated in striated muscles by Ca/calmodulin dependent myosin light chain kinase
3
Q
Essential light chain (ELC)
A
fine tuning of the myosin motor function
4
Q
Myosin thick filament
A
equal to the length of the A-band
Each contain an ATPase catalytic site and an actin binding site
5
Q
Tropomyosin and troponin
A
Regulate skeletal muscle contraction Tropomyosin blocks myosin from binding thin filament troponin C- binds Ca I- strong affinity for actin T- Binds the tropomyosin
6
Q
Slow Twitch Type 1
A
Fatigue resistant Red myoglobin Oxidative High mito Low glycogen
7
Q
Fast twitch type 2A
A
Fatigue resistant red myoglobin oxidative higher mito abundant glycogen
8
Q
Fast twitch type 2B
A
Fatigable White- low myoglobin glycolytic fewer mito high glycogen
9
Q
Satellite cells
A
mobilized when needed to
- proliferate
- differentiate
- fuse into multinucleate myfibers
10
Q
Myostatin
A
Gene that controls muscle fiber growth
- loss of myostatin causes uncontrolled muscle hypertrophy
- exercise and growth hormone decrease myostatin in the muscle
