Ch 8 Flashcards
Metabolic pathways
Totality of an organism’s chemical reactions
Anabolic pathways
Consume energy to build complex molecules from simpler ones
Catabolic pathways
Releases energy by breaking down complex molecules into simpler compounds
Kinetic energy
Energy associated with motion
Heat/thermal energy
Kinetic energy associated w/ random movement of atoms or molecules
Potential energy
Energy that matter possesses because of its location or structure
Chemical energy
Potential energy available for release in a chemical reaction
Entropy
Disorder of a System
Spontaneous rxn
occurs without energy input
Can happen en quickly or slowly
Increases entropy of the universe
Non spontaneous reaction
Requires energy input or energy coupling
Decreases the entropy of the universe
Free energy 🔼 G
Energy that can do work
Related to a change in enthalpy or change in total energy
Only processes with a negative G are spontaneous
Higher G
More free energy
Less stable
Greater work capacity
Reactants are favored
Spontaneous change
Free energy decreases
System becomes more stable
Released free energy can now do work
Lower G
Less free energy
More stable
Less work capacity
Exergonic reactions
Proceeds with a het release of free energy and is spontaneous
Energy is released
Catabolic reactions
Breaking things down
Endergonic reaction
Absorbs free energy from its surroundings and is non spontaneous
Energy is required
Anabolic pathways
Consumes energy to build pathways
Energy coupling
How cells manage energy resources
Use of an exergonic process to drive an endergonic one
Most are mediated by ATP
Work cells can do
Chemical, transport, mechanical
Enzyme
Speed up metabolic reactions by lowering energy barrier
Catalytic protein
Catalyst
Chemical agent that speeds up a reaction without being consumed by the reaction
Activation energy
Initial energy needed to start a chemical reaction
Substrate
Reactant that an enzyme acts on
Active site
Region on enzyme where the substrate binds
Induced fit
Brings chemical groups of the active site into positions that enhance their ability to catalyze the reaction
Cofactors
Nonprotein enzyme helpers
May be inorganic or organic
Coenzyme
Organic cofactor, includes vitamins
Competitive inhibitors
Reduces enzyme productivity by blocking substrates from entering active sites
Enzyme inhibitors
Bind to enzyme by weak interactions, this is reversible
Attaching to enzyme is irreversible
Non competitive inhibitors
Binds to enzyme away from active sites altering the shape of the enzyme
Allosteric regulation
Can either inhibit or stimulate an enzyme
Any case in which a protein’s function at one site is affected by binding to a separate site
cooperativity
Form of allosteric regulation that can amplify enzyme activity
