The interaction between which protein and ion initiates contraction of skeletal muscle?

With the word calcite wich completes the analogy mineral, erosion, marble, or aragonite

How can you tell the difference between rough er from smooth er?

Which statement about relative potential energy of electrons is correct? a. an electron in the 2 p orbital of the second electron shell has more potential energy than an electron in the 2 s orbital of the second electron shell. b. an electron in the 2 p orbital of the second electron shell has more potential energy than an electron in the 3 p orbital of the third electron shell. c. an electron in the 3 p orbital of the third electron shell has more potential energy than an electron in the 2 p orbital of the second electron shell.