Respiration 1

Definitions

Autotrophs

Organisms that absorb light energy for metabolism.

Heterotrophs

Organisms that absorb chemical potential energy for metabolism.

Anabolic reactions

Synthesis of complex substances from simpler ones.

ATP (Adenosine Triphosphate)

Universal energy currency of the cell, used for energy storage and transfer.

Hydrolyzed

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

Chemiosmosis

The process by which ATP is synthesized using the energy from proton gradients.

Coenzymes

Molecules that assist enzymes in catalyzing reactions, e.g., NAD and FAD.

Respiratory quotient (RQ)

The ratio of carbon dioxide produced to oxygen consumed during respiration.

Link reaction

Conversion of pyruvate into acetyl CoA; occurs in mitochondrial matrix.

Krebs cycle

Series of reactions that produce ATP, NADH, and FADH2 while releasing CO2.

Oxidative phosphorylation

Process of ATP synthesis powered by the electron transport chain and proton gradient.

Anaerobic respiration

Respiration that occurs without oxygen, yielding less ATP.

Ethanol pathway

Pathway for fermentation in yeast, converting pyruvate into ethanol.

Lactate pathway

Pathway for anaerobic respiration in muscle cells, converting pyruvate into lactate.

Respirometer

Device used to measure the rate of respiration by observing gas volume changes.

Substrate-level phosphorylation

Direct formation of ATP by transferring a phosphate group to ADP during glycolysis.

Proton gradient

Differential concentration of protons across a membrane, used to drive ATP synthesis.

Hydrogen carrier molecules

Molecules like NAD and FAD that transport hydrogen atoms during respiration.

Energy density

Amount of energy produced per unit mass of a substrate during respiration.