Buffers Flashcards
What is pH?
Amount of H+ ions
Importance of pH in bio systems (blood)
Proper functionality
- bio systems cannot handle huge changes in pH
Optimal pH level of blood
7.4 (more basic)
What maintains blood pH?
3 different types of buffer systems
1) protein
2) phosphate
3) bicarbonate
Buffer
A solution (or substance - made of weak acids and bases) that has the ability to MAINTAIN pH and BRING IT BACK to its OPTIMAL level
How do buffers perform their function?
By adding or removing H+ ions
How do protein buffers work in blood?
- lower pH if it rises above 7.4 by making the blood slightly more acidic (release more H+ ions)
- increase pH if falls below 7.4 by making it more basic/decreasing acidity (take up H+ ions)
Protein role in Buffer Systems
Proteins are the most important and widely operating buffers in the body fluid
Zwitterion
An ion that is simultaneously negatively and positively charged
- ex. amino acids
NH3(+)-CHR-COO(-)
Types of protein buffers
Intracellular or extracellular
Main protein buffer function
Intracellular
- includes hemoglobin (transport oxygen)
- plasma proteins function as buffers
Protein buffers include
Basic and acidic protein buffer groups that acts as H+ depletors or doners
Phosphate Buffer System ions
- Hydrogen phosphate
HPO4 (2-) - Dihydrogen phosphate
H2PO4 (1-)
How do phosphate buffers work in blood?
- if the pH drops below 7.4 (acidic), HYDROGEN PHOSPHATE accept all additional H+ ions to reestablish equilibrium between OH and H ions
- if the pH increases above 7.4 (basic), DIHYDROGEN PHOSPHATE releases H+ to increase pH
Bicarbonate Buffer System function
- maintain pH in mammal blood
- major role in formaion of acid in stomach
- neutralise pH of chyme that enters small intestine
- manages acid/base imbalances
- manages release of excess CO2 (by-product of cellular respiration)
