Lecture 7-Metabolism and Energy Flashcards
what is metabolism
all of an organisms/cell’s chemical reactions, managing the materials and energy resources of the cell
anabolism
rxns that require energy to build the cell
catabolism
rxns that release energy from nutrient breakdown
what is energy
capacity to cause change or do work
potential energy
energy stored due to position or composition
kinetic energy
energy due to movement
first law of thermodynamics
energy cannot be created nor destroyed only converted from one form to another
second law of thermodynamics
entropy of the universe is always increasing
entropy
measure of randomness/disorder of a system
_____ is the most disordered of energy therefore a rxn is _______ if disorder of a universe increases
heat;spontaneous
exergonic
reactants over products
-negative G change
-spontaneous
-thermodynamically favourable
-energy released
endergonic
products over reactant
-positive G change
-nonspontaneous
-thermodynamically unfavorable
-energy requiring
energy coupling
energy from exergonic rxns power endergonic rxns
ATP hydrolysis
releases energy
-powers endergonic rxns
enzymes
catalysts that provide an alternate energy path for a rxn to proceed with a lower activation energy
-highly regulated
-not consumed by rxn
how enzymes work
bind and act on substrates via active site
enzymes lower the activation energy of a reaction by
1. bring reactants ______
2. active site contains ________________favourable for rxn
3. physically stress bonds to be ________
4. covalently stabalize rxn intermediate
5. place substrates in ________
- closer together
- chemical environment favourable for rxn
- broken
- covalently stabalize rxn intermediate
- correct orientation
competitive enxyme inhibitors
binds to active site but does not participate in rxn
noncompetitive inhibitors
binds to a site on enzyme that is not an acitve site and block enzyme activity
