lecture 12 thermodynamics part2 Flashcards
what two rxns are constantly occurring in cells
exergonic and endergonic
thermodynamically favorable rxns
cells replace ordered forms of matter with les ordered forms
-energy is released
what does a thermodynically favorable rxn include
many catabolic rxns
thermodynamically unfavorable rxns
-what does it include a lot of
structures from less ordered materials
-E is supplied
-includes a lot of anabolic rxns
metabolism is
both catabolic and anabolic rxns
when does passive transport occur
when solutes diffuse across a membrane along [] gradients
what determined is rxn is exergonic or endergonic
delta G value
G not prime is wat
Gibbs free energy change under standard conditions
-all rxn conditions initially at 1M []
what is delta G dependent on
ratio of [] or products/[] of reactants
what is cellular work often couples to
ATP hydrolysis
chem work powers
endergonic rxns
transport work transfers…
moleq against [] gradient
Mechanical work moves….
structures within the cell
ATP hydrolysis yields
ATP energy
where is energy from oxidation of nutrients stored
in high energy bond
energy stored in high energy bind is ______
released
is high energy bond weaker or strong than other covalent bonds
weaker
does formation of new low energy bond release more or less energy than it takes to break high energy bond in ATP
more
ATP hydrolysis provides what for chem rxns
energy
energy comes from
ATP
ATP hydrolysis results in what
phosphorylated intermediate that allows energy coupling. this drives chem work
what is phosphorylated intermediate also important in
ATP driven active transport of solutes across membrane
-cells are constantly using and making ATP
why must a living cell take in nutrients
to harvest energy to maintain high levels of ATP at steady state far from equilivrium
ATP hydrolysis = favorable or unfavorable
favorable
what happens when the cells dies
[] of ATP and ADP shifts to their equilibrium values (much more ADP than ATP)
for chem rxns what does equilibrium not mean
does not mean that there is an = [] of reactants and products or that all reactants are converted to products
