elektratransport

Elektratransport is the movement of electrons through a sequence of carriers or through a conducting medium, enabling energy transfer or chemical change. In biology it refers to cellular processes such as respiration and photosynthesis, while in physics and materials science it describes electron flow in metals and semiconductors.

In mitochondria, the electron transport chain comprises complexes I–IV, ubiquinone (CoQ) and cytochrome c in the inner mitochondrial membrane. Electrons from NADH and FADH2 pass through the chain, releasing energy used to pump protons across the membrane. The resulting proton motive force powers ATP synthase to convert ADP and Pi into ATP; oxygen is the final electron acceptor, forming water.

In chloroplasts, the photosynthetic electron transport chain in the thylakoid membrane uses light to excite electrons from water, transferring them through a series of carriers to produce ATP and NADPH, while releasing oxygen as a byproduct.

In physical contexts, elektron transport describes electron flow under electric fields (drift) or concentration gradients (diffusion) in materials such as metals and semiconductors. The efficiency and behavior depend on carrier density and mobility, scattering, temperature, and material structure. Applications include energy conversion devices (batteries, fuel cells), electronics, and catalysis. Experimental methods to study these processes include spectroscopy, electrochemistry, and various transport measurements.