Chapter 4 Flashcards
metabolism
biomedical modification and use of organic molecules and energy to support activities of life
kinetic energy
energy of motion
potential energy
energy an object has because of its location or chemical structure
1st law of thermo
energy cannot be created or destroyed
2nd law of thermo
enthropy is always increasing
spontaneous reactions
reactions that occur without putting in energy
enthalpy
potential energy in a system
exothermic
reaction that releases energy
endothermic
reaction that absorbs heat
free energy
portion of energy that is available to do work
exergonic reaction
releases free energy
endergonic reaction
requires free energy to work
catabolic pathway
energy is released by breaking down complex molecules into simpler ones
anabolic pathway
energy is used to create complicated molecules from smaller ones
energy coupling
process where atp is hydrolyzed, the terminal phosphate group is transferred to the reactant molecule
phosphorylation
addition of a phosphate group to a molecule
atp/adp cycle
continual hydrolysis and resynthesis of atp
activation energy
energy required to start a reaction
catalysis
chemical agent that accelerates the rate of a reaction
enzymes
most common biological catalysts
substrate
reactant that the enzyme acts on
enzyme specificity
an enzyme that can only work on a specific molecule
active site
small region where enzyme interacts with substrate
cofactor
nonprotein group that binds precisely to the enzyme for catalytic activity
coenzymes
other cofactors often derived from enzymes
saturated
when enzymes are cycling as fast as possible
competitive inhibition
inhibitor binds to an active site
noncompetitive inhibition
inhibitor binds to enzyme somewhere other than the active site
allosteric regulation
enzyme activity controlled by reversible binding of a regulary molecule to an allosteric site
allosteric site
location outside the active site
allosteric activator
increases enzyme activity
allosteric inhibitior
decreases enzyme activity
feedback inhibition
when products of reaction act as regulators
ribozymes
rna based catalysts
