Muscles
Below is a mixed up summary of a muscle contraction
Can you put it in the correct order?
Order
1
2
3
4
5
6
7
8
9
10
11
Brief summary of a muscle contraction
Motor nerve¶s impulse action to neuromuscular junction
Sliding action of actin over myosin (Sliding Filament
Theory).
Calcium ions released from SR and binds with troponin
Myosin globular heads combines with actin binding sites
Tropomyosin covers binding sites, myosin no longer
bound
Impulse stops, calcium or ATP depleted, calcium ions
return to SR
Sodium ions ³leak´ into muscle cell initiating action
potential which travels T-tubules to sarcoplasmic
reticulum (SR).
Conformational shift of tropomyosin, ³uncovers actin
binding sites´.
With ATP present, ATPase splits ATP to ADP + P +
Energy
Acetylcholine(ACH) released by synaptic vesicles,
crosses synaptic cleft (Acetylcholinesterase enzyme
breaks down ACH).
Calcium actively ³pumped´ back to SR
Hint to help 1 and 11 are correct
Correct
order