When NADH donates electrons to protein complex 1 (embedded in the mitochondrial membrane) during respiration, protein complex 1 is

Electron carriers of the electron transport chain

Explanation:

NADH reduces the electron carrier by donating an electron, releasing NADH+.

answer; /// i believe that the correct answer is ( monophasic ); ethinyl estradiol- ethynodiol diacetate is a monophasic oral contraceptive agent; ///

the solute can move "downhill," from regions of higher to lower concentration, relying on the specificity of the protein carrier to pass through the membrane. this process is called passive transport or facilitated diffusion, and does not require energy.