Muscular System Flashcards
What three ways is ATP used in muscle contractions?
Aerobic respiration, Anaerobic respiration (glycolysis) and Creatine phosphate.
What is a sarcolemma?
The cell membrane of a skeletal muscle
What are the Z-lines?
Define the limits of the sarcomere
What are the I - bands?
The region that only contains actin filaments
What is the M - Line
Are the centre of the Myosin filaments
What is the H - zone?
It lies within the A band, it is the space of the A band that only contain Myosin filaments, the h zone ends where myosin and actin interlock
What is the A- band?
Contains the H- zone and M-line, it is the same length as the myosin filaments. Myosin and actin interlock in the A- band
When the sarcomere contracts what happens to the I bands?
They shrink
When the sarcomere contracts what happens to the H- zone
It shrinks
When the sarcomere contracts what happens to the Z-line?
Nothing
When the sarcomere contracts what happens to the A band?
Nothing
What is the sliding filament theory of contractions?
Myosin head attaches to actin,
Myosin pivots pulling the actin filaments towards the centre.
The cross bridge detaches a new ATP binds with the myosin
Cocking of the myosin head occurs when ATP is converted to ADP + P. Another cross bridge can form
What is a tropomyosin?
Is a protein that is wound around the actin
What is a troponin?
It’s a molecule that is bound to tropomyosin that contains calcium ion binding sites
What proteins makes up a myosin?
Myosin proteins
