Biochemistry 4115: Electron Transport and Oxidative Phosphorylation

Flashcards designed to help students review key vocabulary terms and concepts related to electron transport and oxidative phosphorylation in biochemistry.

Glycolysis

The metabolic pathway that converts glucose into pyruvate, producing ATP and NADH.

Citric Acid Cycle

A series of chemical reactions used by all aerobic organisms to generate energy through the oxidation of acetate derived from carbohydrates, fats, and proteins.

Oxidative Phosphorylation

The process by which ATP is formed as electrons are transferred from NADH and FADH2 to oxygen by a series of electron carriers.

Electron Transport Chain

A group of proteins and coenzymes located in the inner mitochondrial membrane that facilitate the transfer of electrons from reducing agents to oxygen.

Complex I

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

Complex II

The protein complex that oxidizes succinate to fumarate and transfers electrons to coenzyme Q.

Complex III

The protein complex that transfers electrons from reduced coenzyme Q to cytochrome c.

Complex IV

The protein complex that reduces molecular oxygen to water, completing the electron transport chain.

Proton Gradient

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

ATP Synthase

An enzyme that uses the energy from the proton gradient to synthesize ATP from ADP and inorganic phosphate.

FADH2

A reduced electron carrier produced in the TCA cycle that transfers electrons to the electron transport chain.

NADH

A reduced form of NAD+ that carries electrons to the electron transport chain for ATP production.

Mitochondrial Matrix

The space within the inner membrane of the mitochondria where the citric acid cycle occurs.

Cristae

The folds in the inner mitochondrial membrane that increase the surface area for chemical reactions.

Coenzyme Q (Ubiquinone)

A mobile electron carrier in the electron transport chain that transports electrons from Complexes I and II to Complex III.

Cytochrome c

A small heme protein that plays a key role in the electron transport chain, transferring electrons from Complex III to Complex IV.

Reduction

The gain of electrons by a molecule, often involving a decrease in oxidation state.

Substrate-level phosphorylation

A type of ATP synthesis that occurs when a phosphate group is transferred directly from a phosphorylated substrate to ADP.

Enzyme

A biological catalyst that speeds up chemical reactions by lowering the activation energy.

Porin

A transmembrane protein in the outer mitochondrial membrane that allows the passive diffusion of small molecules.

Electrochemical gradient

The gradient consisting of both a concentration difference and a charge difference across a membrane.