Overview
This lecture segment explains how the electron transport chain (ETC) functions in bacterial metabolism, highlighting electron movement, increasing electronegativity, and ATP synthesis.
Electron Transport Chain Basics
- The electron transport chain consists of a series of molecules with increasing electronegativity.
- Electronegativity refers to how strongly a molecule attracts electrons, similar to magnets of increasing strength.
- Electrons move stepwise through the chain, jumping from weaker to stronger "magnets."
- The last and strongest electron acceptor is called the final electron acceptor.
- In various organisms, the final electron acceptor may be oxygen, nitrogen, sulfur, or another highly electronegative molecule.
Flow of Electrons and ATP Production
- Electrons are transferred through the chain and ultimately to the final electron acceptor.
- The stepwise movement of electrons generates energy, similar to water powering a hydroelectric dam.
- The energy released by electron flow drives the enzyme ATP synthase.
- ATP synthase uses this energy to produce large amounts of ATP, the cell’s main energy molecule.
Key Terms & Definitions
- Electron Transport Chain (ETC) — a series of molecules that transfer electrons to create a flow of energy.
- Electronegativity — the strength with which a molecule attracts electrons.
- Final Electron Acceptor — the last molecule in the chain to accept electrons (often oxygen, nitrogen, or sulfur).
- ATP Synthase — the enzyme that synthesizes ATP using energy from electron flow.
Action Items / Next Steps
- Review the main steps of electron flow in the electron transport chain.
- Highlight key molecules involved in the ETC in your textbook.