ENERGY Flashcards
What is an anabolic reaction
links simple molecules to make complex ones
energy STORING
require energy
What is a catabolic reaction
break down complex molecules into simple ones
release energy
What is the difference between potential E and Chemical bond E
Pot E goes into kinetic which turns into heat
Chem E goes into rapid molecular motions which turn into heat
What is the driving force for energy conversions
dispersing energy!!!
How can a cell release free energy/drive a reaction
by dispersing energy and increasing entropy in the universe
How do cells disperse energy and increase entropy in the universe (2 ways)
- with a chem rxn creating disorder in the cell (ie. digesting a polymer)
- with a chem rxn releasing heat which generates disorder in the surroundings
How to anabolic rxns occur
by coupling endergonic reactions to exergonic ones
What should be the overall sign of Gibbs free E of coupled reactions and why
negative because only reactions with negative gibbs energy can be catalyzed
Why is the hydrolization of ATP to ADP and a phosphate ion exergonic
the energy of the P-O bond is much higher than the H-O bond that forms after hydrolysis, because the phosphates are negatively charged, so energy is required to get them near each other to bond
ADP is constantly removed
Some endergonic reactions are (x3)
anabolism, cell movement, active transport
Some exergonic reactions are (x2)
cellular respiration, catabolism
What can be predicted if free energy is known
direction but not rate of reaction
Exergonic reactions proceed only after..
activation energy is added
What is the potential energy of a molecule
a function of the way its electrons are positioned
