catabolic pathways
Releases energy, breaks down molecules, ex) cellular respiration
Anabolic pathways
Consume energy, build up larger molecules, "uphill" reactions, require enzymes to catalyze reactions, ex) photosynthesis
Energy cannot be created or destroyed but it can be transferred
First law of thermodynamics
Entropy
Disorder; randomness; the more randomly arranged a collection of matter is, the greater its ____________
every energy transfer or transformation increases the entropy of the universe
Second law of thermodynamics
Spontaneous
Increase in entropy; process that can proceed without requiring an input of energy
free energy (triangle G)
The portion of a system's energy that can perform work when temperature and pressure are uniform
Exergonic
Release of energy; loses free energy; (triangle G) is negative; spontaneous
Endergonic
Absorbs energy from surroundings; stores energy; (triangle G) is positive; non spontaneous
chemical work, transport work, mechanical work
3 types of work that a cell does
Hydrolysis
What process breaks the phosphate group in ATP
Adenosine triphosphate
What makes up ATP
energy coupling
The use of an exergonic process to drive an endergonic process
Phosphorylation intermediate
The second molecule formed when the phosphate group from ATP is added to another molecule
catalyst
A chemical agent that speeds up a reaction without being consumed by the reaction
activation energy (Ea)
the energy required to contort the reactant molecules so the bonds can break
induced fit
Brings chemical groups of the active site into positions that enhance their ability to catalyze the chemical reaction
Cofactors
nonprotein enzyme helpers
Coenzymes
organic cofactors
competitive inhibitor
A substance that mimics the substrate, competing for the active site
noncompetitive inhibitor
A substance that binds to the enzyme away from the active site, altering the shape
allosteric regulation
when a regulatory molecule binds to a protein at one site and affects the protein's function at another site
allosteric activator
Binding of an activator to a regulating site stabilizes the shape that has functional active sites
allosteric inhibitors
Binding of an inhibitor stabilizes the inactive form of the enzyme