Chapter 7 Vocabulary Flashcards
Acetyl coenzyme A; the entry compound for citric acid cycle in cellular respiration, formed from a two-carbon fragment of pyruvate attached to a coenzyme.
Acetyl CoA
A catabolic pathway for organic molecules, using oxygen as the final electron acceptor in an electron transport chain and ultimately producing ATP. This is the most efficient catabolic pathway and is carried out in most eukarytoic cells and many prokaryotic organisms.
Aerobic Respiration
Glycolysis followed by the reduction of pyruvate to ethyl alcohol, regenerating NAD and releasing carbon dioxide.
Alcohol fermentation
An iron-containing protein that is a component of electron transport chains in the mitochondria and chloroplasts of eukaryotic cells and the plasma membranes of prokarytoic cells.
Cytochrome
A complex of several membrane proteins that functions in chemiosmosis with adjacent electron transport chains, using the energy of a hydrogen ion (proton) concentration gradient to make ATP. ATP synthases are found in the inner mitochondrial membranes of eukarytotic cells and in the plasma membranes of prokaryotes.
ATP synthase
`The catabolic pathways of aerobic and anaerobic respiration, which break down organic molecues and use an electron transport chain for the production of ATP.
Cellular respiration
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. Under aerobic conditions, most ATP synthesis in cells occurs by chemiosmosis.
Chemiosmosis
A chemical cycle involving eight steps that completes the metabolic breakdown of glucose molecules begun in glycolysis by oxidizing acetyl CoA (derived from pyruvate) to carbon dioxide; occurs within the mitochondrion in eukaryotic cells and in the cytosol of prokaryots; together with pyruvate oxidation, the second major stage in cellular respiration.
Citric acid cycle
A sequence of electron carrier molecules (membrane proteins) that shuttle electrons down a series of redox reactions that release energy used to make ATP.
Electron transport chain
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.
Facultative anarobe
A catabolic process that makes a limited amount of ATP from glucose (or other organic molecules) without an electron transport chain and that produces a characteristic end product, such as ethyl alcohol or lactic acid.
Fermentation
A series of reactions that ultimately splits glucose into pyruvate. Glycolysis occurs in almost all living cells, serving as the starting point for fermentation or cellular respiration.
Glycolysis
Glycolysis followed by the reduction of pyruvate to lactate, regenerating NAD with no release of carbon dioxide.
Lactic acid fermentation
Nicotinamide adenine dinucleotide, a coenzyme that cycles easily between oxidized (NAD) and reduced (NADH) states, thus acting as an electron carrier.
NAD
The complete or partial loss of electrons from a substance involved in a redox reaction.
Oxidation
The production of ATP using energy derived from the redox reactions of an electron transport chain; the third major stage of cellular respiration.
Oxidative phosphorylation
An organism that only carries out fermentation or anaerobic respiration. Such organisms cannot use oxygen and in fact may be poisoned by it.
Obligate anarobe
The potential energy stored in the form of a proton electrochemical gradient, generated by the pumping of hydrogen ions (H+) across a biological membrane during chemiosmosis.
Proton-motive force
A chemical reaction involving the complete or partial transfer of one or more electrons from one reactant to another; short for reduction-oxidation reaction.
Redox reaction
The complete or partial addition of electrons to a substance involved in a redox reaction.
Reduction
The enzyme-catalyzed formation of ATP by direct transfer of a phosphate group to ADP from an intermediate substrate in catabolism.
Substrate-level phosphorylation
