Cellular Respiration



a reaction that requires the presence of oxygen


a reaction that does not require the presence of oxygen

channel protein

protein permitting specific substances to be moved across a cell membrane


the movement of ions across a semipermeable membrane down their electrochemical gradient, which results in a charge that can be used as a source of energy

citric acid cycle

a series of chemical reactions used by all aerobic organisms to release ATP


a non-protein chemical, such as NAD and FAD, that helps an enzyme function


a substance made of atoms of two or more elements bonded together in a certain ratio


subatomic particles with a negative charge

electron transport chain

a series of electron transporters that move electrons from NADH and FADH2 to oxygen molecules; protons are pumped from the mitochondrial matrix to the intermembrane space, and oxygen is reduced to form water


an anaerobic breakdown of a substance, such as glucose, that produces a limited amount of ATP for a cell


metabolic pathway in which glucose is broken down into pyruvate in the cytoplasm of the cell


a molecule with the same chemical formula as another molecule, but with a different three dimensional structure


an enzyme that drives the conversion of a molecule into its isomer form


on a molecular level, the biological processes that build or break molecules; on an organismal level, all of the chemical reactions within an organism that provide cells with the capacity to acquire energy and use that energy to carry out different functions


a substance that is formed during metabolism or required for metabolic processes


the movement of water molecules across a semipermeable membrane from an area of lower concentration of solute to higher concentration of solute

oxidation reaction

a reaction that involves the removal of an electron from a compound

oxidative phosphorylation

when ATP is produced using chemiosmosis in the mitochondria through an electron transport chain


the addition of a phosphate group to a compound in a chemical reaction

prosthetic groups

non-protein molecules that are required for another protein to be active

proton gradient

a pathway in which protons move from an area of higher concentration to an area of lower concentration

redox reaction

a reaction where oxidation and reduction occur together to form products

reduction reaction

a reaction that involves the addition of an electron to a compound