22 terms

AP Biology Chapter 9 Vocabulary

aerobic respiration
a catabolic pathway that consumes oxygen and oragnic molecules, producing ATP. This is the most efficient catabolic pathway and is carried out in most eukaryotic cells and many prokaryotic organisms.
alcoholic fermentation
glycolysis followed by the conversion of pyruvate to carbon dioxide and ethyl alcohol.
ATP synthase
a complex of several membrane proteins that provide a port through which protons diffuse. This complex functions in chemiosmosis with adjacent electron transport chains, using the energy of a hydrogen ion (proton) gradient to make ATP. found in the inner mitochondrial membrane of eukaryotic cells and in the plasma membrane of prokaryotes.
cellular respiration
the catabolic pathways of aerobic and anaerobic respiration, which break down organic molecules for the production of ATP.
an energy-coupling mechanism that uses energy stored in the form of a hydrogen ion gradient across a membrane to drive cellular work, such as the synthesis of ATP. most ATP synthesis in cells occurs by chemiosmosis.
citric acid cycle
a chemical cycle involving eight steps that completes the metabolic breakdown of flucose molecules begun in glycolysis by oxidizing pyruvate to carbon dioxide; occurs within the mitochondrion in eukaryotic cells and in the cytosol of prokaryotes; the second major stage in cellular respiration.
an iron-containing protein that is a component of electron transport chains in the mitochondria and cholorplasts of eukaryotic cells and the plasma membranes of prokaryotic cells.
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.
facultative anaerobes
an organism that makes ATP by aerobic respiration if oxygen is present but that switches to anaerobic respiration or fermentation if oxygen is not present.
a catabolic process that makes a limited amount of ATP from glucose without an electron transport cahin and that produces a characteristic end product, such as ethyl alcohol or lactic acid.
the splitting of glycose into pyruvate. occurs in almost all living cells, serving as the starting point for fermentation of cellular respiration.
lactic acid fermentation
glycolysis followed by the conversion of pyruvate to lactate, with no release of carbon dioxide.
nicotinamide adenine dinucleotide, a coenzyme that can accept an electron and acts as an electron carrier in the electron transport chain.
obligate anaerobes
an organism that only carries out fermentation or anaerobic respiration. such organisms cannot use oxygen and in fact may be poisoned by it.
the loss of electrons from a substance involved in a redox reaction.
oxidative phosphoryalation
the production of ATP using energy derived from the redox reactions of an electron transport chain; the third major step of cellular respiration.
oxidizing agent
the electron acceptor in a redox reaction
proton-motive force
the potential energy stored in the form of an electrochemical gradient, generated by the pumping of hydrogen ions across a biological membrane during chemiosmosis.
redox reaction
a chemical reaction involving the complete or partial transfer of one or more electrons from one reactant to another. short for oxidation-reduction reaction.
reducing agent
the electron donor in a redox reaction.
the addition of elecrongs to a substance involved in a redox reaction.
substrate-level phosphorylation
the formation of ATP by an enzyme directly transferring a phosphate group to ADP from an intermediate substrate in catabolism.