Module2_Lecture_5_Respiration_I

Cellular Respiration

A series of catabolic reactions that convert the energy in fuel molecules into ATP.

Glycolysis

The partial oxidation of glucose that produces pyruvate, ATP, and reduced electron carriers.

Mitochondrion

The organelle where cellular respiration occurs, specifically pyruvate oxidation, citric acid cycle, and oxidative phosphorylation.

Pyruvate Oxidation

The process where pyruvate is oxidized to acetyl-CoA, linking glycolysis to the citric acid cycle.

Citric Acid Cycle (Krebs Cycle)

A cycle that results in the complete oxidation of fuel molecules, generating ATP and reduced electron carriers.

Oxidative Phosphorylation

The stage of cellular respiration where ATP is synthesized using energy from the electron transport chain.

Electron Transport Chain (ETC)

A sequence of complexes that transfer electrons from electron carriers to oxygen, driving ATP synthesis.

NAD+ / NADH

NAD+ is the oxidized form, while NADH is the reduced form; both act as important electron carriers.

FAD / FADH2

FAD is the oxidized form, while FADH2 is the reduced form; both participate in the electron transport chain.

Substrate-Level Phosphorylation

A process of ATP generation where an enzyme/substrate complex catalyzes the direct transfer of a phosphate group to ADP.

Proton Gradient

The difference in proton concentration across a membrane, used by ATP synthase to generate ATP.

ATP Synthase

An enzyme that synthesizes ATP by utilizing the energy from the proton gradient across the inner mitochondrial membrane.

Reduction

The gain of electrons by a molecule during a chemical reaction.

Oxidation

The loss of electrons from a molecule during a chemical reaction.

Acetyl-CoA

A key molecule in metabolism that is formed from pyruvate and links glycolysis to the citric acid cycle.

Chemiosmosis

The movement of ions across a selectively permeable membrane, down their electrochemical gradient, which is essential for ATP production.