Chapter 8: An Introduction to Metabolism

	the total of an organism's chemical reactions; an emergent property of life that arises from interactions between molecules within the orderly environment of the cell
	begins with a specific molecule, which is then altered in a series of defined steps, resulting in a specific product; each step of teh pathway is catalyzed by a specific enzyme
	a metabolic process that breaks down complex molecules into simpler compounds; example = cellular respiration because it breaks glucose into carbon dioxide and water; the energy that is stored becomes available to do work within the cell
	a metabolic process that consumes energy to build complicated molecules from simpler molecules; example = synthesis of a protein from amino acids; energy comes from catabolic pathways
	the study of how energy flows through living organisms
	the capacity to cause change
	the relative motion of an object
	kinetic energy associated with random movement of atoms or molecules
	the energy that matter possesses because of its location or structure when it is at rest; due to arrangement of atoms
	the type of energy that refers to the potential energy available for release in a chemical reaction; glucose, for example, has a high amount of this
	the study of energy transformations that occur in a collection of matter
	a rule that states that the energy of the universe is constant; energy can be transferred and transformed, but it cannot be created or destroyed
	a rule that states that every energy transfer or transformation increases the entropy (disorder) of the universe; unstoppable trend toward randomization of the universe as a whole
	the portion of a system's energy that can perform work when temperature and pressure are uniform throughout the system, as in a living cell; this type of energy is a measure of a system's instability, meaning its tendency to change to a more stable state
	disorder of the universe
	order of the universe
	the variable of free energy that represents a generally unstable system
	the variable of free energy that represents a generally stable system
	the type of reaction that proceeds with a net release of free energy; because the chemical mixture loses free energy, Gibbs free energy is negative; it is a spontaneous reaction
	the type of reaction that absorbs free energy from surroundings; because energy is stored in molecules, Gibbs free energy is positive; the reaction is nonspontaneous
	the type of cellular work that includes the pushing of endergonic reactions, which would not occur spontaneously, such as the synthesis of polymers from monomers
	the type of cellular work that includes the pumping of substances across membranes against the direction of spontaneous movement
	the type of cellular work that includes the beating of cilia, the contraction of muscle cells, and the movement of chromosomes during reproduction
	the use of an exergonic process to drive an endergonic one; ATP is responsible for mediating this, and it acts as an energy source
	this molecule is composed of ribose, adenine, and a chain of three phosphate groups
	the state of a molecule when it receives a phosphate, such as in ATP hydrolysis, making it more reactive (less stable) than the original molecule
	a macromolecule that acts as a catalyst; without this, pathways of metabolism would be congested because reactions would take so long
	a chemical agent that speeds up a reaction without being consumed by the reaction; enzymes are examples of these
	the initial investment of energy for starting a reaction; the energy required to destabilize the reactant molecules so their bonds can break; also, the amount of energy needed to push reactants over a "hill" so that the "downhill" part of the reaction can begin
	the reactant an enzyme acts on
	the entity that forms when an enzyme bonds to a substrate, in which the enzyme's catalytic reaction converts the substrate to the product of the reaction
	a pocket or groove on the surface of an enzyme where catalysis occurs; there is only one of these per enzyme; this is formed by a few amino acids while others construct a frame for it
	a molecule in a metabolic pathway that is a product in one step and used as a reactant in another step; it can be crossed out from the overall equation
	the equation for the hydrolysis of ATP
	the amount of Gibbs free energy that results from the hydrolysis of ATP
	the equation for the synthesis of ATP
	the amount of Gibbs free energy that results from the synthesis of ATP
	the equation for aerobic cellular respiration
	the amount of Gibbs free energy that results from aerobic cellular respiration
	in this step of catalysis, the substrate enters the active site; the enzyme changes shape so the active site can enfold the substrate
	in this step of catalysis, the substrate and enzyme bond via weak bonds
	in this step of catalysis, the active site lowers the activation energy for the reaction
	doing these things: a) acting as a template for substrate orientation, b) stressing the substrates and stabilizing the transition state, c) providing a favorable microenvironment, and d) participating directly in catalytic reaction, are ways to do what in a reaction?
	the state that an enzyme is said to be in if as soon as the product of one reaction leaves, a new substrate enters the active site
	nonprotein helpers for catalytic reactions; these may be bound tightly to an enzyme as a permanent resident, or may be bound loosely and reversibly along the substrate
	cofactors that are inorganic; examples of these are vitamins
	chemicals that selectively reduce or prevent the action of a specific enzyme
	reversible inhibitors that resemble the normal substrate molecule and compete for admission into the active site; these reduce productivity by blocking substrates from entering active sites; these can be overcome by producing more substrates to outnumber them; poisons are an example of these with strong bonds
	this occurs when a molecule that resembles substrate bonds to the active site, thereby blocking the substrate; this occurs with weak bonds; the higher the concentration of the inhibitor, the slower the reaction; not used intentionally
	these molecules do not directly compete with substrates--instead, they bind to another part of the enzyme, causing it to change its shape so that the active site becomes less effective at conversion
	this occurs when a molecule bonds to some other location on an enzyme, causing a conformational change, which blocks the active site; after the molecule leaves, however, the enzyme returns to its original shape; may result in either inhibition or enhanced activity of an enzyme
	the alternate location on an enzyme where noncompetitive inhibitors bond
	a -G with the addition of a catalyst ________________ the reaction
	a -G with no addition of a catalyst ________________ the reaction
	a +G coupled with an exergonic reaction and with the addition of a catalyst ____________ the reaction
	a +G without a coupled reaction and without a catalyst ________________ the reaction
	the change in G for an exergonic reaction (energy outward)
	the change in G for an endergonic reaction (energy inward)
	the state of a reaction at which just enough energy is reached to break the bonds of reactants
	a mechanism that amplifies the response of an enzyme to a substrate by leading one substrate molecule to prime an enzyme's acceptance of additional substrate molecules; when one subunit of an enzyme has an induced fit, other subunits mimic that fit; example = hemoglobin: as soon as one oxygen bonds to a heme group within the polypeptide chain of hemoglobin, the other three polypeptide chains develop a greater affinity to oxygen
	an occurrence in which a metabolic pathway is switched off by the inhibitory binding of its end product to an enzyme that acts early in the pathway; this prevents the cell from wasting chemical resources; when an end product stops or slows its own production
	where enzymes for cellular respiration are found within a cell
	the model for enzymes that says that enzymes are highly specific, and as a result, there is only one substrate that fits in an enzyme's active site; criticism: because proteins can be denatured, it is somewhat unlikely that rigid guidelines can be followed exactly
	the model for enzymes that says that as the substrate and active site approach each other, each influences the other's shape so they mold together; compared to a proper handshake: both entities conform to make a good grip in order to interact
	1) molecules must collide, 2) molecules must collide with sufficient energy, 3) molecules must collide with proper orientation
	optimal temperature range for enzymes in the human body (in degrees Celsius)
	optimal pH range for enzymes in the human body