cell respiration

ATP

Adenosine triphosphate; the molecule that distributes energy within cells.

Glycolysis

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

Aerobic respiration

Cell respiration that requires oxygen and yields a large amount of ATP.

Anaerobic respiration

Cell respiration that occurs without oxygen and produces less ATP.

Phosphorylation

The process of adding a phosphate group to a molecule, often to activate or deactivate it.

NAD+

Nicotinamide adenine dinucleotide; a coenzyme used as a hydrogen and electron carrier in respiration.

Oxidation

A chemical reaction that involves the loss of electrons or hydrogen from a molecule.

Reduction

A chemical reaction that involves the gain of electrons or hydrogen by a molecule.

Electron Transport Chain (ETC)

A series of protein complexes in the mitochondrial membrane that transfers electrons and produces ATP.

Chemiosmosis

The movement of protons down a gradient through ATP synthase, generating ATP.

Krebs cycle

A series of reactions in the mitochondrial matrix that generates ATP, NADH, and FADH2 from acetyl CoA.

Substrates for cellular respiration

Molecules like glucose and fatty acids that provide energy during respiration.

Hydrolysis of ATP

The process of breaking down ATP into ADP and inorganic phosphate, releasing energy.

Lactate

A product of anaerobic respiration in humans, formed from pyruvate.

Fermentation

A metabolic process that converts sugar to acids, gases, or alcohol in the absence of oxygen.

Active transport

Movement of substances across a cell membrane against their concentration gradient, using ATP.

Pyruvate

The end product of glycolysis, which can be further metabolized in aerobic or anaerobic respiration.

Acetyl CoA

A molecule derived from pyruvate that enters the Krebs cycle for aerobic respiration.

Coenzyme A

A coenzyme that plays a key role in the synthesis and oxidation of fatty acids.

Decarboxylation

The removal of a carboxyl group from a compound, releasing carbon dioxide.

Oxidative phosphorylation

The production of ATP using the energy derived from electron transport and oxygen as the final electron acceptor.

Proton gradient

A difference in proton concentration across a membrane, driving ATP synthesis.

Reduced NADH

The form of NAD+ after it has gained electrons and hydrogen during cellular respiration.

Gas exchange

The physical process of exchanging gases like oxygen and carbon dioxide in the body.

Sodium-potassium pump

A type of active transport that moves sodium ions out of and potassium ions into the cell, using ATP.