Which is a form of active transport? proteins create openings on another side of the cell membrane. proteins open up channels in the cell membrane. proteins enter and exit the cell freely. proteins push molecules through the cell membrane.

Do the following statements describe actin, myosin, both of the proteins or neither of the proteins? (a) contains a binding site for calcium (b) found in the i band (c) exists in a globular (g) form and a filamentous (f) form (d) contains a binding site for atp (e) is a component of the thin filament (f) is a component of the thick filament