BUFFER SYSTEM

BUFFER isIS a solution that resist changes in ph

General Components

A buffer contains:

~a weak acid & saltor

~a weak base & salt

THE buffer system in our body

There are three important system in our bodies

1 -bicarbonate buffer system 2 -phosphate buffer system3 -protein buffer system

First bicarbonate buffer systemIs carbon dioxide converted into

bicarbonate ions in the blood

Carbonic Acid – Bicarbonate Buffer System

Respiratory component Renal

CO2 + H2O H2CO3 H + + HCO3 –

(H2CO3 is a ‘volatile’ acid as CO2 exhaled)

• Carbonic Acid –

Bicarbonate Buffer

System ~Most

important in the ECF

Importance of bicarbonate is disposal by the lung

• Protein Buffer

Systems

~Important in ECF and ICF

~Interact with other buffer

systems

Protein themselves can act buffer They contain ionizable group carboxyl

and amino group

2-The phosphate buffer system:

●Nucleic acid break down to yield phosphoric acid.

Phosphoric acid (H3PO4 )changes into dihydrogen phosphate (H2PO4

- ). This dihydrogen phosphate is an

excellent buffer .14