Aerobic - occurring or living in the presence of free or dissolved oxygen
Anaerobic - occurring or living in conditions without free or dissolved oxygen
Krebs cycle - the cycle in cellular respiration that completes the breakdown of the intermediate products of glycolysis, releasing energy; also, a source of carbon skeletons for use in biosynthesis reactions
Electron transport system - the process in which electrons are transferred from one carrier molecule to another in photosynthesis and in cellular respiration; results in storage of some of the energy in ATP molecules
NAD+ - nicotinamide adenine dinucleotide; an electron and hydrogen carrier in cellular respiration
NADH - the hydrogen-carrying form of NAD+
FADH2 - flavin adenine dinucleotide; in cellular respiration, a hydrogen-carrying form of FAD
FAD - flavin adenine dinucleotide; combines with two hydrogen atoms during cellular respiration to form FADH2
Pyruvate - the 3-carbon compound that is the end product of glycolysis
Lactic acid – an acid formed from NADH and pyruvate at the end of glycolysis when little oxygen is available
Lactic acid fermentation - the anaerobic pathway at the end of glycolysis that recycles NAD+ and provides a small amount of ATP until oxygen becomes available
Coenzyme A - a coenzyme present in all cells and necessary for cellular respiration and for fatty acid metabolism
