Which of the following statements about the electron transport chain in cell respiration is CORRECT? The electron transport chain of proteins contains pores that are leaky to H. The loss in free energy of the electron initially donated by NADH is used to transport H+ across the inner mitochondrial membrane against its electro The ATP synthase generates a H+ gradient across the inner mitochondrial membrane. The electron transport chain of proteins uses ATP to pump H+ across the inner mitochondria membrane against its electrochemical gradient

Sourav PanDecember 12, 2024

Answered

The correct statement is:

The loss in free energy of the electron initially donated by NADH is used to transport H+^++ across the inner mitochondrial membrane against its electrochemical gradient.

Explanation:

• The loss in free energy of the electron initially donated by NADH is used to drive the proton pumps (such as Complexes I, III, and IV) across the inner mitochondrial membrane, creating a proton gradient. As electrons move through the electron transport chain, their energy is used to pump protons against their electrochemical gradient, contributing to the formation of the proton gradient needed for ATP synthesis.
• The electron transport chain of proteins contains pores that are leaky to H+^++ is incorrect. The electron transport chain does not have “leaky” pores. Instead, it uses proton pumps to actively transport protons across the inner mitochondrial membrane.
• The ATP synthase generates a H+^++ gradient is incorrect. ATP synthase uses the proton gradient (created by the electron transport chain) to generate ATP, but it does not generate the gradient itself.
• The electron transport chain of proteins uses ATP to pump H+^++ is incorrect. The electron transport chain does not require ATP to pump protons. It uses the energy released from electrons moving through protein complexes to pump protons.