Lecture on Proton-Motive Force and ATP Synthesis

This collection of flashcards covers key vocabulary and concepts related to the lecture on the proton-motive force, ATP synthesis, and the mechanisms of cellular respiration.

Proton-Motive Force (PMF)

The stored energy from a proton gradient across a membrane that drives ATP synthesis.

ATP Synthase

An enzyme that synthesizes ATP from ADP and inorganic phosphate, powered by the proton gradient.

Chemiosmotic Hypothesis

The theory proposed by Peter Mitchell that a proton gradient is the link between electron transport and ATP synthesis.

Coupling

The phenomenon where electron transport and ATP synthesis are linked through the proton gradient.

Uncoupling

When protons leak back across the inner membrane without producing ATP, releasing energy as heat instead.

Malate-Aspartate Shuttle

A shuttle system that transfers electrons from cytoplasmic NADH to mitochondrial NAD+, preserving energy.

Glycerol-3-Phosphate Shuttle

A shuttle system that transfers electrons from cytoplasmic NADH to FAD in the mitochondria, yielding less ATP.

Energy Charge

A measure of the cell's energy status that controls metabolic pathways based on ATP, ADP, and AMP levels.

IF1 (Inhibitor Factor 1)

A protein that inhibits ATP synthase from running in reverse during conditions of low pH.

UCP-1 (Uncoupling Protein 1)

A protein in brown adipose tissue that allows protons to flow back across the membrane, generating heat instead of ATP.

Leber Hereditary Optic Neuropathy (LHON)

The most common mitochondrial disease caused by mutations in mtDNA-encoded Complex I, leading to sudden vision loss.

Electron Transport Chain (ETC)

A series of protein complexes that transfer electrons and pump protons to create a proton gradient for ATP synthesis.

Oligomycin

An antibiotic that inhibits ATP synthase by blocking the proton channel, causing gradient buildup.

DNP (2,4-Dinitrophenol)

An uncoupler that dissipates the proton gradient, increasing oxygen consumption but decreasing ATP synthesis.

Nobel Prize

An award given to Peter Mitchell in 1978 for his chemiosmotic hypothesis on ATP synthesis.

H+/ATP Ratio

The number of protons required to synthesize one ATP molecule, influenced by the number of c-subunits in ATP synthase.