Biophysics Flashcards
ampiphathic molecules
polar and non polar end
brownian motion
molecules in a sol. move due to thermal energy
mols move randomly due to collisions with each other
turgor pressure
diffusion in presence of barriers
osmolarity
number of moles per unit volume
thermodynamics of a reaction tell us…
whether a chemical reaction can be used as energy currency
whether the cell has to work to make a reaction happen
internal energy
capacity of a system to do work
exothermic reaction
releases energy
internal energy of products less than reactants
endothermic reaction
internal energy of products greater than reactants
energy absorbed
enthalpy
heat released by a chemical reaction
enthalpy change
energy released by a reaction minus work released to surroundings
entropy
measures how disordered a system is
microstate
arrangement of each molecule in the system at a single instant
Gibbs free energy
maximum useful work we can extract from a process in an open system
reaction rate
change in concentration of a reactant or product with time
kinetic law
molecules will react if they collide with sufficient kinetic energy to overcome an activation barrier
particle speed depends on…
mass and temperature
first order reaction
decomposition
e.g. radioactive decay
second order reaction
2 molecules collide to determine rate
what is free H+ also known as?
hydroxonium / H3O
acid
substance that produces H+ ions by dissociation
base
substance that releases hydroxide ions
buffers
large vol of weak acid w conjugate base
large vol of weak base w conjugate acid
pKa
how strong a buffer is
henderson hasselbach equation
describes how pH differs in a buffer
free energy in a system
weighted sum of partial molar gibbs energy aka chemical potential of each component
nernst potential
voltage difference across membrane caused by transferring just enough permanent ions to create an electrostatic barrier against further flow of ions
osmotic pressure
stretching force on cell membrane caused by an imbalance of ions on either side
