apbio chap 6 vocab

Metabolism

totality of an organisms chemical reactions which manage the material and energy resources of the organism

metabolic pathway

A series of chemical reactions that either builds a complex molecule or breaks down a complex molecule into simpler compounds.

catabolic pathway

A metabolic pathway that releases energy by breaking down complex molecules to simpler compounds.

anabolic pathway

A metabolic pathway that consumes energy to synthesize a complex molecule from simpler compounds.

bioenergetics

the overall flow and transformation of energy in an organism

thermal energy

kinetic energy due to random motion of atoms and molecules;heat

chemical energy

energy available in molecules for release in a chemical reaction

entropy

measure of disorder, or randomness

free energy

portion of a biological system that can preform work; G; can not be changed, even in an enzyme catalyzed reaction

exergonic reaction

spontaneous chemical reaction in which there is a net release of free energy

endergonic reaction

non-spontaneous chemical reaction in which free energy is absorbed from surroundings

Equilibrium

condition in which reactants and products of a chemical reaction are formed at an equal rate

energy coupling

the use of energy released from an exergonic reaction to drive an endergonic reaction

Adenosine Triphosphate

ribonucletotide commonly involved in energy coupling, usually through phosphorylation of other molecules in a hydrolysis reaction

hydrolysis

chem reaction that breaks bonds between two molecules by the addition of water

atp cycle

formation of adenosine diphosphate and subsequently atp through repeated dephosphorylation and phosphorylation

enzyme

biological catalyst that increases the rate of a reaction without being consumed by the reaction

catalyst

A chemical agent that selectively increases the rate of a reaction without being consumed by the reaction.

activation energy

The amount of energy that reactants must absorb before a chemical reaction will start; reduced in an enzymatic reaction

substrate

the reactant on which an enzyme works

active site

specific enzyme region that binds the substrate and thst forms the pocket in which catalysis occurs

induced fit

Caused by entry of the substrate, the change in shape of the active site of an enzyme so that it binds more snugly to the substrate.

catalysis

the process of orienting or stressing substrate by an enzyme resulting in a decrease in activation energy

denatured

describes a protein that has lost its conformation due to the disruption of weak interactions and chem bonds, resulting in a loss of function

cofactor

nonprotein molecule/ion that is required for the proper functioning of an enzyme

coenzyme

organic cofactor; often a vitamin

competitive inhibitor

substance that reduces the activity of an enzyme by entering the active site in place of the substrate whose structure it mimcis

noncompetitive inhibitor

A substance that reduces the activity of an enzyme by binding to a location remote from the active site, changing its conformation so that it no longer binds to the substrate.

allosteric regulation

the binding of molecule at one site on a protein that affects the function of the. protein at a different site

cooperativity

A kind of allosteric regulation whereby a shape change in one subunit of a protein caused by substrate binding is transmitted to all the other subunits, facilitating binding of additional substrate molecules to those subunits.

feedback inhibition

method of metabolic control in which the end product of a metabolic pathway acts an an inhibitor of an enzyme within that pathway