Right. So, let’s talk about buffer solutions.
Buffer solutions are specific recipes that
contain either a weak acid and its conjugate
base or a weak base and its conjugate acid.
This is very important because what we are
using or what we are doing is we’re making
sure that we can control to some extent what
happens when we add subsequent amounts of
base and subsequent amounts of acid. We cannot
do this, if we deal with a strong acid or
strong base since dissociation occurs in both
cases almost completely.
Buffers have the property of being able to
oppose changes in pH despite the addition
of acid base. So, in this case, what it means
is that, if you like, for example, were to
look at a biological fluid, let’s say, for
the sake of argument, blood, the idea that
minute changes in acid concentration would
be allowable would be to effectively stop
a lot of the proteins from being able to work.
Stopping proteins from work would soon lead
to death pretty much. And so, therefore, we
need to have our own buffers from a biological
perspective in order to oppose any minute
changes in the concentrations of acids in
our bodies through a whole host of different
Buffer solutions are important not just in
maintaining experimental setups, but also
in terms of maintaining the integrity and
pH of chemical and biological setups. Studies
involving proteins always required buffer
solutions to preserve their structures since,
as you can appreciate, most proteins are actually
quite intolerant to variation in acidity.
Changes in acidity actually can result in
changes in tertiary and quaternary structures
to these proteins and render them non-functional.
Enzymes, in particular, are often highly sensitive
to changes in pH. And indeed one of the ways
in which proteins can be denatured i.e. enzymes
can be stopped doing what they do, is by treating
them to an acid and heat bath.
Buffers can also help to preserve drugs in
solutions for periods of time by present...
preventing acid or base degradation.
Water itself has no buffering capacity. Pure
water has a pH of 7, as we said before.
And 1.0 litres or 1 litre of water plus a
tiny amount of hydroxide ion has a pH of 12.3.
When we do the same with acid, let’s say
0.02 mol of hydrochloric acid, this would
result in the formation of a solution with
a pH of 1.7. So, water is easily changed in
terms of its concentration of available [H+]
by virtue of minute changes in the concentrations
of free acid and free base that are provided.
A buffered solution would be able to maintain
its pH within a few hundredths of a pH unit
after the addition of similar amounts of acid
or base. And that’s the desire when it comes
to a good buffer.