Statement 3 is the best choice
All the options are incorrect. The correct answer will be THE NUMBER OF HYDROGEN IONS MOVING DOWN THE PROTEIN CHANNEL.
A proton pump is found in the inner membrane of mitochondria which is also known as hydrogen ion pump. The hydrogen ion is pumped across the inner mitochondrial membrane depending on the proton gradient.
Venus is the answer. That planet has a dense atmosphere of CO2, which has produced a runaway greenhouse effect.
Most genes contain the information needed to make functional molecules called proteins. this is the answer on APEX
