What is a Buffer?
What does the bicarbonate buffer system do?
- the main buffer in ECF; also in ICF - a mixture of carbonic acid (H2CO3 - weak acid)) and bicarbonate (HCO3- - weak base)
pH is a measurement of what?
the concentration of free hydrogen ions in a solution (Bound hydrogen ions do not increase the pH)
what are the 2 types of buffers
physiological and chemical
When a base (hydroxyl ions) are added to a solution the buffer does what?
releases hydrogen ions and they bind to the hydroxyl ions (this prevents the pH changing)
what is a chemical buffer?
accept or donate hydrogen ions to maintain the pH of a solution
what are the three main chemical buffers, and what is the main buffer in the blood?
bicarbonate buffer (main buffer in the blood) phosphate buffer protein buffer
When an acid is added to a solution it resists the increase/change in the pH by doing what?
binding to the free hydrogen ions
what is a buffer?
buffers are substances of systems that resist a change in pH of a solution
When do physiological buffers act?
if the chemical buffers are insufficient
when do chemical buffers act?
immediately (to stabilise pH)
