Unit 3 Flashcards
(60 cards)
define metabolism
all of an organisms chemical reactions
metabolic pathway
begins with a specific molecule, which is then altered in a series of defining steps, resulting in a certain product
catabolism
breaking down larger molecules into smaller ones
anabolism
building up larger molecules from smaller ones
kinetic energy
energy of motion
potential energy
stored energy
thermodynamics
study of relationships among various forms of energy
1st law of thermodynamics
energy cannot be created or destroyed
2nd law of thermodynamics
energy transfer or transformation increases the entropy of the universe
true or false? all energy conversions are 100% efficient
false
biological organisms need a constant input of _____________ to maintain their low entropy
energy
H = G + S
Total energy (H, enthalpy) = usable energy (G, Gibbs free energy) + unusable energy (S, entropy)
if delta G is negative
the reaction is spontaneous, exergonic
exergonic
energy is released
if delta G is positive
the reaction is not spontaneous, endergonic
endergonic
requires energy
if delta G is zero
reaction is at equillibrium
delta G for hydrolysis of ATP
-7.3 kcal/mol
catalyst
substance that speeds up the rate of a chemical reaction
catalysts lower…
activation energy
physically, catalysts…
bring molecules close and bend bonds
enzyme-substrate interaction
-substrate and enzyme make a temporary union
-substrate is inserted into the active site
-the process is irreversible
enzymes need optimal conditions such as
temperature, salt, pH
irreversible enzyme inhibitors
bind to enzyme via covalent bonds
