Exam 3: Metabolism and Enzymes Flashcards
metabolism
the chemical reactions that occur in living cells through various pathways that utilize enzymes
catabolism
a specific type of metabolism that breaks down molecules to release energy
anabolism
a specific type of metabolism that uses energy to construct molecules for use in the cell
potential energy
the energy in a system due to the position or arrangement of the system
kinetic energy
the energy in a system due to motion
Gibb’s free energy
the amount of available potential energy in a system, or the amount of work that can be extracted from the system
enthalpy
the total energy of a system
entropy
the disorder of a system; systems tend toward increased entropy
spontaneous process
a reaction that will occur without the addition of external energy; the rate of the reaction is not related to its spontaneity; includes exergonic reactions
nonspontaneous process
a reaction that needs additional energy to proceed; includes endergonic reactions
exergonic reaction
a reaction in which energy flows from the system to the environment; exergonic reactions are spontaneous
endergonic reaction
a reaction in which energy flows from the environment to the system; endergonic reactions are nonspontaneous
enzyme
proteins that increase the rate of reactions, usually by lowering the activation energy
activation energy
the amount of energy needed in order to catalyze a chemical reaction
substrate
molecule that binds to the active site of an enzyme and forms a substrate-enzyme complex