Question

As the electron transport system carriers move electrons by redox reactions, they actively pump _____ across the membrane maintaining a concentration gradient.

Answer 1

Answer;
As the electron transport system carriers move electrons by redox reactions, they actively pump hydrogen ions across the membrane maintaining a concentration gradient. 

Explanation;
Electron transport is a phase of cellular respiration in which majority of ATP is formed. During this phase electron carriers that are reduced during glycolysis and citric acid cycle to NADH+ H+ and FADH2. The carriers then donate electrons and protons to the electron carrier proteins of the ETC, with oxygen being the final acceptor. 

Answer 2

As the electron transport system carriers move electrons by redox reactions, they actively pump protons across the membrane maintaining a concentration gradient.

What is Redox Reaction?

Redox reactions are those reactions where oxidation and reduction always take place together because every electron that is lost by one atom through oxidation is gained by another atom through reduction.

The proton gradient produced by proton pumping during the electron transport chain is used to synthesized ATP. In cellular respiration, proton pumps use energy to transport protons from the matrix of the mitochondria to the inter-membranous space.

Therefore, as the electron transport system carriers move electrons by redox reactions, they actively pump protons across the membrane maintaining a concentration gradient.

To learn more about the Electron transport system, refer to the link:

https://brainly.com/question/5145977