During sarcomere contraction, _________ first has to bind to ________ Select one: a. Calcium, troponin b. Calcium, microfilaments c. Sodium, troponin d. Sodium tropomysin e. Potassium, microfilaments

The shortening of _____________ will cause the shortening of a muscle fiber. Z lines     thin filaments     sarcomeres     thick filaments

Cardiomyocytes differ from skeletal muscle cells in that cardiomyocytes ______.   A "do not have actin, myosin, or Z-disk "   B do not have their actin and myosin arranged into sarcomeres and myofibrils   C cannot have action potentials at a high enough frequency for tetani to occur   D have fewer mitochondria and are more reliant on anaerobic respiration   E All of the above are true of heart muscle cells

In a fully contracted sarcomere, the actin myofilaments A. Form the H zone B. Form a Z disc C. Overlap D. Dissapear