activation energy
the minimum energy input that enables reactants to overcome the energy barrier, allowing a chemical reaction to proceed at a noticeable rate.
active site
the specific region on the surface of an enzyme where substrate molecules bind.
ADP
(Adenosine Diphosphate) The compound that remains when a phosphate group is removed from ATP, releasing energy
anabolism
Metabolic pathways that construct molecules, requiring energy.
ATP
(adenosine triphosphate) main energy source that cells use for most of their work
Catabolism
Metabolic pathways that break down molecules, releasing energy.
catalyst
a substance that speeds up a specific chemical reaction without being permanently altered in the process.
cellular respiration
a metabolic process that extracts chemical energy from organic molecules, such as sugars, to generate the universal energy carrier ATP, consuming oxygen and releasing carbon dioxide and water in the process. Has three phases: glycolysis, the Krebs cycle,
chemical energy
potential energy that is stored in the bonds between atoms and ions
energy
the capacity of any object to do work
enzyme
a macromolecule, usually a protein, that acts as a catalyst, speeding the progress of chemical reactions.
first law of thermodynamics
also called "law of conservation of energy". states that energy can be neither created nor destroyed, but only transformed or transferred from one molecule to another.
heat energy
also called "thermal energy". kinetic energy that is inherent in the random motion of particles in a system that can be transferred to other particles in the system; the portion of the total energy of a particle of matter that can flow from one particle o
induced fit model
A model of substrate-enzyme interaction stating that as a substrate enters the active site, the parts of the enzyme shift about slightly to allow the active site to mold itself around the substrate.
kinetic energy
the energy that a system possesses as a consequence of its state of motion; energy of motion
metabolic pathway
A series of enzyme-controlled chemical reactions in a cell in which the product of one reaction becomes the substrate for the next.
metabolism
the capture, stage, and use of energy by living organisms.
oxidation
the loss of electrons by one atom or molecule to another.
photosynthesis
a metabolic process by which organisms capture energy from sunlight and use it to synthesize sugars from carbon dioxide and water.
potential energy
stored energy
product
a substance that is formed by a chemical reaction
reactant
a substance that undergoes a chemical reaction
redox reaction
an oxidation-reduction, a chemical reaction in which electrons are transferred from one molecule or atom to another.
reduction
the gain of electrons by one atom or molecule from another
second law of thermodynamics
the law stating that all systems, such as a cell or the universe, tend to become more disordered, and that the creation and maintenance of order in a system requires the transfer of disorder to the environment. (think of closet)
substrate
the particular substance on which an enzyme acts. only a substrate will bind to the active site of an enzyme.