Cellular Respiration: Key Concepts in Energy Production and Metabolism

Oxidation-reduction (redox) reactions

Reactions involving electron donors and acceptors.

Coenzymes

Molecules like NADH and FADH2 that assist enzymes in biochemical reactions.

Energy currency molecules

Molecules such as ATP and GTP that store and transfer energy in cells.

Oxidation

Removal, or loss, of an electron (OIL).

Reduction

Addition, or gain, of an electron (RIG).

Electron carriers

Molecules that transport electrons in redox reactions.

NADH

An electron carrier that undergoes oxidation and reduction reactions.

FADH2

An electron carrier that undergoes oxidation and reduction reactions.

ATP: Adenosine Triphosphate

A molecule that releases energy when breaking down by removing phosphates.

Substrate-level phosphorylation

Process where an enzyme catalyzes the addition of phosphate to ADP to form ATP.

Oxidative phosphorylation

An oxygen-requiring process that utilizes chemiosmosis to produce ATP in the mitochondria.

Glycolysis

The first stage of cellular respiration that occurs in the cytoplasm, producing 2 pyruvate, 2 NADH, and 2 ATP.

Anaerobic pathways

Pathways that break down pyruvate in the absence of oxygen, yielding low ATP.

Aerobic pathways

Pathways that break down pyruvate in the presence of oxygen, producing much more ATP.

Krebs cycle (TCA cycle)

A series of reactions that produce CO2, NADH, and FADH2 from Acetyl CoA.