metabolism - Answers The totality of an organism's chemical reactions.
energy - Answers The capacity to do work.
kinetic energy - Answers The energy of motion.
heat - Answers A form of energy that is transferred between systems or objects with different
temperatures.
potential energy - Answers Stored energy that has the potential to do work.
chemical energy - Answers Energy stored in the bonds of chemical compounds.
thermodynamics - Answers The study of energy transformations.
phosphorylation - Answers The addition of a phosphate group to a molecule.
substrate - Answers The reactant on which an enzyme works.
active site - Answers The region on an enzyme where the substrate binds.
enzyme-substrate-complex - Answers The temporary complex formed when an enzyme binds to its
substrate.
induced fit - Answers The change in shape of an enzyme to better fit the substrate.
cofactor - Answers A non-protein molecule that assists in enzyme activity.
coenzyme - Answers An organic cofactor that assists enzymes.
vitamin - Answers Organic compounds that are essential for normal growth and nutrition.
metabolic pathway - Answers A series of chemical reactions in a cell that builds or breaks down a
molecule.
catabolic pathway - Answers A metabolic pathway that releases energy by breaking down complex
molecules.
anabolic pathway - Answers A metabolic pathway that consumes energy to build complex molecules.
closed system - Answers A system that does not exchange matter with its surroundings.
open system - Answers A system that exchanges matter and energy with its surroundings.
first law of thermodynamics - Answers Energy cannot be created or destroyed, only transformed.
second law of thermodynamics - Answers In any energy transfer, the total entropy of a system will
increase over time.
entropy - Answers A measure of disorder or randomness in a system.
oxidative phosphorylation - Answers A metabolic pathway that uses energy released by the electron
transport chain to power ATP synthesis.
substrate level phosphorylation - Answers A process of forming ATP by directly transferring a
phosphate group to ADP from a phosphorylated intermediate.
chemiosmosis - Answers The movement of ions across a selectively permeable membrane, down their
electrochemical gradient, which is used to generate ATP.
electron transport chain - Answers A series of protein complexes and other molecules that transfer
electrons from electron donors to electron acceptors via redox reactions.
cytochrome - Answers A heme-containing protein that plays a key role in the electron transport chain.
prosthetic groups - Answers Non-polypeptide units that are tightly and permanently attached to
proteins, aiding in their function.
proton-motive force - Answers The force that promotes the movement of protons across membranes
during chemiosmosis.
obligate anaerobe - Answers An organism that cannot survive in the presence of oxygen.
facultative anaerobe - Answers An organism that can survive with or without oxygen.
redox reaction - Answers A chemical reaction in which the oxidation states of one or more substances
are changed.
oxidized - Answers When a substance loses electrons during a chemical reaction.
reduced - Answers When a substance gains electrons during a chemical reaction.
electron donor - Answers The substance that donates electrons in a redox reaction.
electron acceptor - Answers The substance that accepts electrons in a redox reaction.
glycolysis - Answers The metabolic pathway that converts glucose into pyruvate, producing ATP and
NADH.
TCA cycle - Answers A series of chemical reactions used by all aerobic organisms to generate energy
through the oxidation of acetyl-CoA.
mitochondrial electron transport chain (ETC) - Answers A series of protein complexes located in the
inner mitochondrial membrane that facilitate electron transfer and proton pumping.