Acetyl CoA
combination of an acetyl group derived from pyruvic acid and coenzyme A, which is made from pantothenic acid (a B-group vitamin).
Aerobic Respiration
process in which organisms convert energy in the presence of oxygen.
Anaerobic
process that does not use oxygen.
Anaerobic Cellular Respiration
process in which organisms convert energy for their use in the absence of oxygen.
ATP synthase (also, F1F0 ATP synthase)
membrane-embedded protein complex that adds a phosphate to ADP with energy from protons diffusing through it.
Chemiosmosis
process in which there is a production of adenosine triphosphate (ATP) in cellular metabolism by the involvement of a proton gradient across a membrane.
Citric Acid Cycle (also, Krebs cycle)
series of enzyme-catalyzed chemical reactions of central importance in all living cells.
Dephosphorylation
removal of a phosphate group from a molecule
Fermentation
process of regenerating NAD+ with either an inorganic or organic compound serving as the final electron acceptor, occurs in the absence; occurs in the absence of oxygen.
GLUT Protein
integral membrane protein that transports glucose.
Glycolysis
process of breaking glucose into two three-carbon molecules with the production of ATP and NADH.
Isomerase
enzyme that converts a molecule into its isomer.
Krebs Cycle (also, citric acid cycle)
named after Hans Krebs who first identified the steps in the pathway in the 1930s in pigeon flight muscles; see citric acid cycle.
Oxidative Phosphorylation
production of ATP using the process of chemiosmosis and oxygen.
Phosphorylation
addition of a high-energy phosphate to a compound, usually a metabolic intermediate, a protein, or ADP.
Prosthetic Group (also, prosthetic cofactor)
molecule bound to a protein that facilitates the function of the protein.
Pyruvate
three-carbon sugar that can be decarboxylated and oxidized to make acetyl CoA, which enters the citric acid cycle under aerobic conditions; the end product of glycolysis.
Redox Reaction
chemical reaction that consists of the coupling of an oxidation reaction and a reduction reaction.
Substrate-level Phosphorylation
production of ATP from ADP using the excess energy from a chemical reaction and a phosphate group from a reactant.
TCA cycle (also, citric acid cycle)
named after the group name for citric acid, tricarboxylic acid (TCA); see citric acid cycle.
Ubiquinone
soluble electron transporter in the electron transport chain that connects the first or second complex to the third.