How Muscles Contract Flashcards
Thick filaments
Myosin
Thin filaments
Actin
How are myosin and actin arranged
They overlap which is responsible for light and dark bands that can be seen in skeletal muscles
What are actin filaments attached to
Structure called the z line
What is the region from one z line to another called
Sacromere, it’s the functional unit of muscle contractions
What is the role of calcium
It is the trigger for muscle contraction
What do myosin heads have to do during a single contraction
Attach and detach
What must the muscle cells have a continuous supply of?
ATP, without it the myosin heads would stay attached which would keep muscles contracted
What are the three sources of energy for muscle contraction?
- Breakdown of creatine phosphate.
- Aerobic cellular respiration.
- Fermentation.
What happens to the store to ATP molecules after a few muscle twitches
They are spent. When contraction continues, ATP is regenerated from stored creatine, phosphate, aerobic, cellular respiration, and fermentation
Breakdown of creatine phosphate
• Builds up when muscles are resting
•Provides energy for eight seconds of intense activity
Aerobic, cellular respiration
• requires oxygen
• synthesized in muscle cells
• can store oxygen and make it ready for mitochondria when CR begins.
Fermentation
When oxygen has been used up, muscle cells carry out fermentation
