Chapter 8 Flashcards
the form of cellular respiration found in some prokaryotes in which a molecule other than oxygen is used in the ATP-producing process
anaerobic respiration
the partial or full loss of electrons from a substance
oxidation
substance-the electron donor-from which the electrons are lost during oxidation
oxidized
the partial or full gain of electrons to a substance
reduction
substance-the electron acceptor-that gains electrons during reduction
reduced
coupled oxidation-reduction reaction in which electrons are removed from a donor molecule and simultaneously added to an acceptor molecule
redox reactions
a coenzyme that serves as an electron carrier
nicotinamide adenine dinucleotide (NAD+)
stage of cellular respiration in which sugars such as glucose are partially oxidized and broken down into smaller molecules
glycolysis
an enzymecatalyzed reaction that transfers a phosphate group from a substrate to ADP
substrate-level phosphorylation
stage of cellular respiration in which the threecarbon molecules pyruvate is converted into a 2-carbon acetyl group that is completely oxidized to carbon dioxide
pyruvate oxidation
series of reactions in which acetyl groups are oxidized completely to carbon dioxide and some ATP molecules are synthesized
citric acid cycle
synthesis of ATP in which ATP synthase uses an H+ gradient built by the electron transfer system as the energy source to make the ATP
oxidative phosphorylation
stage of cellular respiration in which high-energy electrons produced from glycolysis, pyruvate oxidation, and the citric acid cycle are delivered to oxygen by a sequence of electron carriers
electron transfer system
a membrane-spanning protein complex that couples the energetically favorable transport of protons across a membrane to the synthesis of ATP
ATP synthase
series of reactions in which acetyl groups are oxidized completely to carbon dioxide and some ATP molecules are synthesized
citric acid cycle/ Krebs cycle/ tricarboxylic acid cycle
stage of cellular respiration in which the 3carbon molecule pyruvate is converted into a 2-carbon acetyl group that is completely oxidized to carbon dioxide
pyruvic acid oxidation
series of electron carriers that alternately pick up and release electrons ultimately transferring them to their final acceptor, oxygen
mitochondrial electron transfer system
protein with a heme prosthetic group that contains an iron atom
cytochromes
stored energy that contributes to ATP synthesis as well as to the cotransport of substances to and form mitochondria
proton-motive force
model proposing that mitochondrial electron transfer produces an H+ gradient and that the gradient powers ATP synthesis by ATP synthase
chemiosmotic hypothesis
process in which electrons carried by NADH are transferred to an organic acceptor molecule rather than to the electron transfer system
fermentation
reaction in which pyruvate is converted into lactate
lactate fermentation
reaction in which pyruvate is converted into ethyl alcohol and CO2 in a 2-step series that also converts NADH into NAD+
alcoholic fermentation
organism in which fermentation is he only source of ATP
strict anaerobes
