Energy Transformations

1st law of thermodynamics

energy cannot be created nor destroyed

2nd law of thermodynamics

during every energy transformation, entropy increases

exergonic

releases energy

spontaneous

endergonic

absorbs energy

non spontaneous

chemical work

pushing of endergonic reactions that wouldn’t occur spontaneously

synthesis of polymers from monomers

transport work

pumping substances across membranes against direction of spontaneous movement

ex) active transport

mechanical work

using ATP from hydrolysis to cause movement of motor proteins

energy coupling

using the energy from an exergonic reaction to drive an endergonic reaction

ex) ATP from cellular respiration can be used to drive photosynthesis

ex2) energy released from ATP hydrolysis can power an endergonic reaction

enzyme

protein that acts as a catalyst (chemical agent that speeds up a reaction without being used by the reaction)

activation energy

energy required to start a reaction

substrate

the reaction the enzyme acts on

active site

the region of the enzyme that binds to the substrate

how do temp and pH affect the rate of enzyme activity?

high temp can destabilize enzyme’s shape and denature it

competitive inhibitors

compete with substrate molecule to bind to active site and blocks the substrate from binding

noncompetitive inhibitors

bind to another part of the enzyme to change the enzyme’s shape (enzyme loses effectiveness)