Chapter 3 Flashcards
metabolism
the sum of all chemical reactions in a cell or organism. Life requires a continual supply of energy.
Catabolic + anabolic
kinetic energy
the energy of motion
potential energy
the stored energy that an object possesses relative from some 0 position
first law of thermodynamics
principle that states that energy can be transferred or transformed, but it cannot be created or destroyed
bond energy
the minimum amount of energy that is required to break a particular type of bond; measured in kJ/mol
activation energy (Ea)
the minimum amount of energy that chemical reactants must absorb to start a reaction
transition state
a temporary condition during a chemical reaction in which the bonds in the reactants are breaking and the bonds in the products are forming
exothermic reaction
a chemical reaction in which potential energy is released, leaving the products with less chemical potential energy than the reactants
endothermic reaction
a chemical reaction in which energy is absorbed, giving the products more chemical potential energy than the reactants
second law of thermodynamics
The randomness (entropy) of a system is always increasing
entropy
a measurement of disorder in a system
spontaneous change
a change that will, once begun, continue on its own under a given set of conditions; does not require a continuous supply of energy
Free energy
energy that can do useful work; also called Gibbs free energy
exergonic reaction
a chemical reaction that releases free energy; the products have less free energy than the reactants “spontaneous” “catabolic” (-G value)
endergonic reaction
a chemical reaction that absorbs free energy; the products have more free energy than the reactants “non spontaneous” “anabolic” (+G)
energy coupling
the transfer of energy from one reaction to another in order to drive the second reaction
catabolic pathway
a pathway in which energy is released and complex molecules are broken down into simple molecules
anabolic pathway
a pathway in which energy is supplied to build complex molecules from simple molecules
ATP
Adenosine triphosphate consists of adenine, 3 phosphate groups and a 5 carbon sugar called ribose
Universal energy currency in living organisms
Regenerated from ADP and H+ during the ATP cycle
Phosphorylation
Transfer of a phosphate group, usually from ATP to another molecule
ATP hydrolysis
an be coupled to endergonic reactions using energy coupling, it releases a lot of free energy and results in the formation of ADP and H+ (Pi)
30.5 KJ/ is are coupled
Bonds are broken down by a catalyzed reaction with H2O
ATP cycle
The cyclic and ongoing breakdown and re- synthesis of ATP
Maud Menten
Michaelis- menten euqation states that the rate of an enzyme catalyzed reaction is proportional to the enzyme substrate complexity
How does a reaction happen
First, all the bonds in the reactants have to break and do to do this they have to be under the correct conditions to overcome the activation energy barrier
