Studied by 2 people
AP Bio
First Law of Thermodynamics
law of conservation of E
E cannot be created nor destroyed
ttal amount of available E in the universe is constant
what are the three types of cellular work
chemical work
transport work
echanical work
chemical work
type of cellular work involving the synthesis of polymers
transport work
type of cellylar work involving the mvt of molecules across the membranes via a protien pump
mechanical work
type of cellular work involving the contraction of muscle cells movement of chromosomes during cell divisions and the movement of cilia and flagella
what type of E do cells utilize
chemical E
where is E stored in the cell
chemical bonds
when bonds are broken, E is released
when bonds are created, E is stored
metabolic pathways
occur in a series of reactions
each reaction in the series is aided by enzymes
complex molecules are either gradually being broken down or created
metabolism
sum total of all metabolic pathways in an organism
second law of thermodynamics
entropy = measure of disorder
process will be spontaneous when it results in an increase of total entropy in the universe
what is the importance of the laws of therm. in organisms
death occurs due to a lostt of E/ a loss of order
exergonic reactions
type of metabolic reaction
increased entropy (increased disorder)
bonds are broken
results in a net release of chemical E
products are at a lower E level than reactants
endergonic reactions
type of metabolic reaction
decreased entropy (decreased disorder)
bonds are created
results in a net absorption of chemical E
E absorbed from the environment is stored in the bonds of molecules
catabolic pathway
type of metabolic pathway
series of reactions that result in a net increase of entropy and a net release of chemical E
complex molecules are graduallly broken down
anabolic pathway
type of metabolic pathway
series of reactions that result in a net decrease of entropy and a net absorption of chemical E
complex molecules sre gradually created
example of cellular work
energy coupling
E released by exergonic reactions are used to drove endergonic reactions
E released by catabolic pathwats are used to drive anabolic pathways
catabolic pathwats don’t directly drive cellular work
cells utilize ATP as an intermediate in energy coupling
ATP
adenosine triphosphate
modified RNA adenine nucleotide (has three phosphates instead of one)
made by cellular respiration or fermentation
E molecules of life because it contains high E bonds
phosphate phosphate bonds
contains high amt of stored E
created via cellular respiration or fermentation
broken down by hydrolysis
harder to make a phosphate bond than it is to break it
to make: metabolic pathway
break: hydrolysis
ATP hydrolysis
atp is hydrolyzed —> ADP, a phosphate group, and E are released
w the help of enzymes, the cell is able to couple the E of ATP hydrolysis to an endergonic rxn = energy coupling
E coupling via ATP
E released by the breakdown of carbon-carbon bonds (monomers)(catabolic pathways) drive the synthesis of ATP (anabolic pathway)
E released by the by thet hydrolysis of ATP (catabolic pathway) drives cellular (anabolic pathways)
phosphorylation
ATP works by coupling the E of the ATP hydrolysis to the phosphorylation of another molecule
E released by the hydrolysis of ATP is used to transfer the new phosphate group to another molecule
recipient of the phosphate group is phosphorlyated
most biomolecules are activated by phosphorylation
phosphorlyated molecules are more reactive/active because the addition of the phosphate causes a change in shape
aided by enzymes
phosphorylation of protein pumps
ATP is hydrolyzed and becomes ADP + P
protein pump is phosphorlyated when P is added, causing it to change in shape which “pumps” material across the membrane
phosphorylation
phosphorylation of all molecules ecvept ADP is coupled with the hydrolysis of ATP
E required to phosphylate ADP is derived from cellular respiration
