Question

Name the three pH control mechanisms in the body and briefly explain how each system works.

Answer 1

The three major buffer systems in the body are carbonic acid bicarbonate buffersystem, phosphate buffer system and protein buffer system.

Carbonic Acid Bicarbonate buffer.

The waste product of cellular respiration is carbon dioxide and it is converted to bicarbonate ion in the blood. After reaching the lungs it is converted to and released as carbon dioxide. When it is in the blood ,it neutralizes acid released due to other metabolic process. In the stomach and duodenum it neutralizes gastric acids and stabilises the intracellular ph of epithelial cells by the secretions of bicarbonate ions into the gastric mucosa.

Phosphate Buffer System.

It operates in the internal fluid of all cells and consists of dihydrogen phosphate ions as the hydrogen ion donor and hydrogen phosphate ion as the the ion accepted. The Dihydrogen phosphate ion literally neutralises any additional hydroxide which enters into the cellular fluid. On the other hand hydrogen phosphate ion neutralize the extra hydrogen ions which enters the cellular fluid.

Protein Buffer System

It helps to maintain acidity in and around the cells and haemoglobin makes an good buffer by binding to small amount of acid in the blood, before they can alter the photo of the blood .other proteins containing aminoacid histidine are also good at buffering.