The aerobic harvesting of energy from food molecules; the breakdown of food molecules, such as glucose, and the storage of potential energy in a form that cells can use to perform work; involves glycolysis, the citric acid cycle, and oxidative phosphorylation
a quantity of heat equal to 1,000 calories. Used to measure the energy content of food, it is usually called a "Calorie"
Short for oxidation-reduction; a chemical reaction in which electrons are lost from one substance (oxidation) and added to another (reduction). Oxidation and reduction always occur together
The loss of electrons from a substance involved in a redox reaction; always accompanies reduction
The gain of electrons by a substance involved in a redox reaction; always accompanies oxidation
An enzyme that catalyzes a chemical reaction during which one or more hydrogen atoms are removed from a molecule
The multistep chemical breakdown of a molecule of glucose into two molecules of pyruvate; the first stage of cellular respiration in all organisms; occurs in the cytoplasmic fluid
citric acid cycle
The metabolic cycle fueled by acetyl CoA formed after glycolysis in cellular respiration. Chemical reactions in the citric acid cycle complete the metabolic breakdown of glucose molecules to carbon dioxide. The cycle occurs in the matrix of mitochondria and supplies most of the NADH molecules that carry energy to the electron transport chains. The second major stage of cellular respiration.
The production of ATP using energy derived from the redox reactions of an electron transport chain; the third major stage of cellular respiration
Energy-coupling mechanics that uses the energy of hydrogen ion gradients across membranes to phosphorylate ADP; powers most ATP synthesis in cells
A cluster of several membrane proteins that function in chemiosmosis with adjacent electron transport chains, using the energy of a hydrogen ion concentration gradient to make ATP
The formation of ATP by an enzyme directly transferring a phosphate group to ADP from an organic molecule
One of the compounds that form between the initial reactant and the final product in a metabolic pathway, such as between glucose and pyruvate in glycolysis
The entry compound for the citric acid cycle in cellular respiration; formed from a fragment of pyruvate attached to a coenzyme
lactic acid fermentation
The conversion of pyruvate to lactate with no release of carbon dioxide.
The conversion of pyruvate from glycolysis to carbon dioxide and ethyl alcohol
An organism that only carries out fermentation; such organisms cannot use oxygen and also may be poisoned by it.
An organism that makes ATP by aerobic respiration if oxygen is present, but that switches to fermentation when oxygen is absent