AP BIO - Unit 3.2 (cell respiration)

cellular respiration

Process that releases energy by breaking down glucose and other food molecules in the presence of oxygen

glycolysis

the breakdown of glucose by enzymes, releasing energy and pyruvic acid.

aerobic respiration

Respiration that requires oxygen

anaerobic respiration

Respiration that does not require oxygen

lactic acid fermentation

the chemical breakdown of carbohydrates that produces lactic acid as the main end product

alcoholic fermentation

the anaerobic process by which yeasts and other microorganisms break down sugars to form carbon dioxide and ethanol

Krebs Cycle (Citric Acid Cycle)

second stage of cellular respiration, in which pyruvic acid is broken down into carbon dioxide in a series of energy-extracting reactions

electron transport chain

A sequence of electron carrier molecules (membrane proteins) that shuttle electrons during the redox reactions that release energy used to make ATP.

oxidative phosphorylation

The production of ATP using energy derived from the redox reactions of an electron transport chain; the third major stage of cellular respiration.

substrate-level phosphorylation

The enzyme-catalyzed formation of ATP by direct transfer of a phosphate group to ADP from an intermediate substrate in catabolism.

electron carriers

molecules that can carry high energy electrons through the electron transport chain (NAD+/NADH, FAD+, FADH2)

inner mitochondrial membrane

The membrane of the mitochondria that is the site of electron transport and chemiosmosis.

intermembrane space

the fluid filled space between the inner and outer mitochondrial membranes

cristae

Infoldings of the inner membrane of a mitochondrion that houses the electon transport chain and the enzyme catalyzing the synthesis of ATP.

mitochondrial matrix

The compartment of the mitochondrion enclosed by the inner membrane and containing enzymes and substrates for the Krebs cycle.

ATP synthase

enzyme that catalyzes the reaction that adds a high-energy phosphate group to ADP to form ATP

oxidation

loss of electrons

reduction

gain of electrons

redox reactions

A chemical reaction involving the transfer of one or more electrons from one reactant to another; also called oxidation-reduction reaction.

pyruvate/pyruvic acid

a three-carbon molecule formed from glucose in anaerobic glycolysis

chemiosmosis

A process for synthesizing ATP using the energy of an electrochemical gradient and the ATP synthase enzyme.