Ap Bio unit 3

Ap Bio unit 3

metabolism

totality of an organism’s chemical reaction

catabolic pathways

breaking down complex molecules into simpler compounds; releases energy

anabolic pathways

building complex molecules from simpler ones; consume/require energy

free energy (G) measures

portion of a system’s energy that can perform work

exergonic reactions ____ free energy

release; product’s G < reactant’s G; - delta G == free energy RELEASED

delta G formula

delta G = gFinal - gInitial

endergonic reactions _____ free energy

absorb; product’s G > reactant’s G; + delta G == free energy REQUIRED

energy coupling

exogonic process to drive an endergonic one

ATP

hydrolysis breaks apart phosphate groups’ bonds; energy released (exergonic) and used for endergonic rxns in the cell

ADP

when ATP is hydrolyzed

activation energy

initial amount of energy the reactants need to absorb to become products

enzymes

proteins that act as biological catalysts; speeds up rxns w/o being used up

how do enzymes speed up metabolic rxns

by lowering the activation energy; do NOT affect delta G of the reaction

substrate

reactants

active site

region on enzyme where substrate binds to

induced fit

binding of substrate to active site

enzyme name

ends in -ase; usually refer to the substrate they bind to / type of reaction they catalyze; ex. lactase catalyzes the hydrolysis of lactose into glucose and galctose

what can denature an enzyme

pH and temp

enzymes’ structure

a sequence of amino acids; folds into specific shape; shape allows for binding to reactants

cofactors

non protein enzyme helps (ex. minerals)

coenzymes

organic cofactors (ex. vitamins)

competitive inhibitor

binds to active site; competes with substrate

noncompetitive inhibitor

binds to another part of the enzyme; enzyme changes shape; active site is nonfunctional

active / inactive conformations

enzymes that can be turned on or off

allosteric regulation

where a protein’s function at one site is affected by binding of a regulatory molecule at another site; can either activate or inhibit