Week 6 (energy and enzymes) Flashcards
first law of thermodynamics
energy can be transformed but not created or destroyed
second law of thermodynamics
energy moves from being localized to being dispersed
closed system ?
exchanges energy but not matter with its surroundings
open system ?
exchanges energy and matter with its surroundings
isolated system ?
does not exchange matter or energy with surroundings
entropy (S)
tendency of energy to become dispersed (spread out)
spontaneous reaction (-)
procces that can occur without an input of energy
tend to be exothermic
delta G = negative
spontaneous
delta G = positive
not spontaneous
enthalpy (H)
total potential energy in a system
reactions tend to be spontaneous if what increases?
entropy
exergonic reaction
delta G = is negative
products contain less free energy
endergonic reaction
delta G= positive
products contain more free energy that reactants
anabolic
synthesis of large molecules
ATP name
adenosine triphosphate
hydrolysis of ATP is what type of reaction
exergonic reaction
enzymes in reactions
-increase rate of reaction by lowering activation energy
-never changes free energy
catalyst
chemical agent that speeds up the rate of reaction without itself taking part in the reaction
3 things enzymes do
-bring reacting molecules together
-change shape of substrate molecules
-expose reactant molecules
competitive inhibition
-inhibitor competes with normal substrate for active site
noncompetative inhibition
does not compete with normal substrate for active site, combines elsewhere
2 effects of temperature on reactions
-temp rises/ rate of reaction increases
-high temps denature proteins/ reducing rate of reaction
