Electron Transport Chain and Cellular Respiration

Vocabulary flashcards on key concepts related to the electron transport chain and cellular respiration.

Electron Transport Chain

A series of proteins that transfer electrons from donors to acceptors, coupling this process with proton transfer across a membrane.

Ubiquinone (Coenzyme Q)

A lipid-soluble electron carrier in the electron transport chain, transferring electrons between protein complexes.

Redox Potential

The ability of a molecule to gain or lose electrons; different electron acceptors have varying redox potentials.

Proton Gradient

A difference in proton concentration across a membrane that generates potential energy used in ATP synthesis.

Complex I (NADH Dehydrogenase)

The protein complex in the electron transport chain that accepts electrons from NADH and pumps protons into the intermembrane space.

Complex II (Succinate Dehydrogenase)

The protein complex that accepts electrons from FADH2 and does not pump protons.

Complex III (Cytochrome c Reductase)

The protein complex that accepts electrons from ubiquinol and pumps protons into the intermembrane space.

Complex IV (Cytochrome c Oxidase)

The final protein complex that accepts electrons from cytochrome c and transfers them to oxygen, forming water.

Oxidative Phosphorylation

The process where ATP is produced in the mitochondria via the electron transport chain and the proton gradient.

Substrate Level Phosphorylation

A process of forming ATP by directly transferring a phosphate group to ADP from another molecule, occurring in glycolysis and the citric acid cycle.

Fermentation

A metabolic process that regenerates NAD+ from NADH in the absence of oxygen, allowing glycolysis to continue.

Lactic Acid Fermentation

A type of fermentation in which pyruvate from glycolysis is converted into lactate and NAD+ is regenerated.

Alcohol Fermentation

A type of fermentation performed by yeast that converts pyruvate into ethanol and carbon dioxide.

Proton Motive Force

The force generated by the electrochemical gradient of protons across a membrane, driving the synthesis of ATP in ATP synthase.

ATP Synthase

An enzyme complex that synthesizes ATP by utilizing the energy from protons flowing down their electrochemical gradient.

Anaerobic Respiration

A form of respiration that uses electron acceptors other than oxygen, resulting in lower ATP yields compared to aerobic respiration.