What is the function of the electron transport chain?

The electron transport chain has a crucial function in cellular respiration, primarily involving the generation of ATP, which is the energy currency of the cell. This process occurs in the inner mitochondrial membrane in eukaryotic cells.

During the electron transport chain, electrons are transferred along a series of proteins and molecules embedded in the membrane. These electrons come from NADH and FADH2, high-energy molecules that are produced during earlier stages of cellular respiration, such as glycolysis and the citric acid cycle. As electrons move through the chain, they release energy, which is used to pump protons (H+) from the mitochondrial matrix into the intermembrane space, creating a proton gradient.

The accumulation of protons in the intermembrane space creates potential energy, much like water behind a dam. This proton gradient then drives protons back into the mitochondrial matrix through ATP synthase, a protein that acts as a turbine. As protons flow through ATP synthase, it catalyzes the conversion of ADP and inorganic phosphate into ATP, effectively synthesizing energy that the cell can use for various functions.

This process of chemiosmosis and the associated ATP production are vital for meeting the energy demands of cellular processes.