Unit 2 Flashcards
metabolism
sum of all chemical reactions that occur in the cell
anabolism + catabolism
metabolic pathway
a sequential series of chemical reactions in living cells; each reaction is catalyzed by a unique enzyme
anabolism
process of using energy to build large molecules from smaller molecules
ex. photosynthesis, synthesis of macromolecules
catabolism
process of breaking down compounds into smaller molecules to release energy
ex. cellular respiration
energy
the ability to do work
kinetic energy vs potential energy
energy of motion vs stored energy
when energy is transferred from one place to another, that is called _____
work
1st law of thermodynamics
energy cannot be created or destroyed, but it can be transformed from one type into another and transferred from one object to another
all energy is accounted for
energy cannot be lost or disappear
chemical energy
potential energy stored in the arrangement of the bonds in a compound
bond energy
measure of the strength or stability of a covalent bond
equal to the minimum amount of energy required to break a particular type of bond
equal to the amount of energy released per mole when a bond is formed
why do free, unbonded atoms have more chemical energy than any compound
because energy is always released when a bond forms
2nd law of thermodynamics
the law of entropy
the entropy of the universe increases with any change that occurs
in every energy transfer or conversion, some of the useful energy in the system becomes unavailable to do work
entropy
measure of disorder
free energy
energy transformations are never 100% efficient. some energy is always lost to the environment, which leads to an increase in entropy.
energy that is not lost, or the portion left that is available to do (useful) work in the given system is free energy.
how are changes in free energy produced
chemical reactions break some bonds and form new ones in products
exergonic reactions
chemical reaction that releases energy
spontaneous and involves a decrease in free energy
products of reaction contain less free energy than reactants (delta G is negative)
endergonic reactions
chemical reaction that requires energy
not spontaneous, and involves an increase in free energy, gains free energy
products of reaction contain more free energy than reactants (delta G is positive)
adenosine triphosphate (ATP)
adenine, phosphate, 3 phosphate groups
last phosphate is unstable
large quantity of energy is released when ATP becomes ADP plus inorganic phosphate P