Question

There are three buffer systems that control the pH of body fluids. One of the buffer systems depeneds on proteins acting as either proton acceptors or proton donors at different pH values. What are the other two biological systems? Explain the way they work.

Answer 1

Other two buffer systems of our body are carbonic acid - bicarbonate buffer system and phosphate buffer system.

H₂CO₃ - HCO₃^- : CARBONIC ACID - BICARBONATE BUFFER
Cellular respiration produces CO₂ as a waste product. This is immediately converted to bicarbonate ion in the blood.

CO₂ + OH^- <==> HCO₃^-

On reaching the lungs it is again converted to and released as carbon dioxide. While in the blood , it neutralises acids released due to other metabolic processes.

HCO₃^- + H⁺ <==> CO₂ + H₂O

In the stomach and deudenum it also neutralises gastric acids and stabilises the intra cellular pH of epithelial cells by the secretions of bicarbonate ions into the gastric mucosa.

H⁺ + OH^- <==> H₂O

PHOSPHATE BUFFER SYSTEM
Phosphate buffer system operates in the internal fluids of all cells. It consists of dihydrogen phosphate ions as the hydrogen ion donor ( acid ) and hydrogen phosphate ion as the ion acceptor ( base ) .

If additional hydroxide ions enter the cellular fluid, they are neutralised by the dihydrogen phosphate ion.

H₂PO₄^- + OH^- <==> HPO₄^2- + H₂O

If extra hydrogen ions enter the cellular fluid then they are neutralised by the hydrogen phosphate ion.

HPO₄^2- + H⁺ <==> H₂PO₄^-

The main purpose of all these buffers is to maintain proper pH within the body system so that all biochemical process can take place.

Hope this helped you!

Thank You So Much! Please Rate this answer as you wish.("Thumbs Up")