Electron Transport Chain

A collection of vocabulary flashcards focused on key concepts related to aerobic metabolism and the electron transport chain.

Electron Transport Chain

A series of proteins in the inner mitochondrial membrane involved in aerobic metabolism.

Structure of the mitochondria

• matrix, intermembrane space, and inner membrane.

• The inner membrane is highly folded (cristae), increasing surface area for ETC proteins.

Cristae

The folds of the inner mitochondrial membrane that increase surface area for ATP production.

ATP Synthase

• Utilizes the proton gradient to convert ADP and inorganic phosphate into ATP.

• H+ ions flow back into the matrix, releasing energy converted to kinetic energy to synthesize ATP.

Chemiosmotic hypothesis

Explains how the proton gradient leads to ATP production.

Proton Gradient

The difference in hydrogen concentration across the mitochondrial membrane that powers ATP synthesis.

Complex I

The first protein complex in the electron transport chain, also known as NADH dehydrogenase.

• Accepts electrons from NADH, recycling NAD+.

• Pumps protons (H+) from the matrix to the intermembrane space.

Complex II

A component that transfers electrons from FADH2 to the electron transport chain.

(associated with complex I) Peripheral protein - doesn’t pump hydrogens

Complex III

The third protein complex in the electron transport chain that pumps protons into the intermembrane space. Accepts electrons from Complex I and II

Complex IV

The final protein complex that transfers electrons to oxygen, producing water and facilitating proton pumping

Energy yield: NADH

Electrons from NADH: pump 3 protons; yield approximately 2.5 ATP.

Energy yield: FADH2

Electrons from FADH2: pump 2 protons; yield approximately 1.5 ATP

Final Electron Acceptor

Oxygen serves as this in the electron transport chain, reacting with electrons and protons to form water.

• Absence of oxygen leads to the cessation of ATP production via oxidative phosphorylation due to buildup in the ETC.