Biochemistry: thermodynamics, water, acids & bases Flashcards
what is the first law of thermodynamics
energy is neither created nor destroyed
what is the second law of thermodynamics
no energy conversion is 100% efficient, i.e. some is unable to do work
what is entropy
the energy that is unable to do work in a reaction, it tends to increase after multiple reactions to an unusable state
what is free energy and how do you calculate it
the energy available to do work
free energy = (E of products) - (E of reactants)
describe an exergonic reaction
free energy of products < free energy of reactants,
-ve Gibbs free energy, and occurs spontaneously
describe an endergonic reaction
need input of energy, +ve Gibbs free energy, often coupled
what bonds are found between water molecules
H bonds, the hydrogen atom is shared between 2 electronegative atoms without the use of electrons
name some important properties of water
it is polar and hydrophilic
what is an acid
a proton donor
what is a base
a proton acceptor
what is the strength of an acid or base based on
their readiness to donate/accept protons, = dissociation constant(Ka/Kb)
what is pH
the number of protons(H atoms) in solution
what is the Henderson Hassleback equation used for
to determine the pH of weak acid in solution
what does a buffer do
it allows a solution to resist a change in pH in response to the moderate addition of acid/alkali
why is pH important
change in pH can change ionisation of proteins, and therefore alter the structure and function
